Okay, good morning. Let us begin with what we started yesterday. So that was the principle of impulse and momentum and before that we discussed work energy theorem and saw that a body typically only in dynamics. For example there was a query about thermodynamics and how does the energy in thermodynamics related with the energy in dynamics and I briefly discussed okay what that means. But in our dynamics course what we discussed is that that there are two types of energies one is the potential energy one is the kinetic energy for conservative fields there is a potential energy but whenever the fields are not conservative for example whenever there is friction then what does the work energy is that the initial kinetic energy plus the work done to move the particle from path 1 to point 2 will be equal to the final kinetic energy of the system. So this was in brief the work energy theorem we also saw that the work energy theorem can be rephrased in the language of conservation of energy if the forces are conservative that T1 plus V1 is equal to T2 plus V2 where V1 can come from gravity when can come from spring energy and if additional electric field example is put in we can also put in the electric field and write down the potential energy but for the time being let us not worry about that our VE as this course is concerned is only based on a potential energy from gravity the potential energy from so we saw that that when a ball for example a cricket ball or a tennis ball okay is hit with either a bat or a racket then in that case for a very brief period a huge amount of force acts on the ball and as a result the momentum changes then we defined what is the concept of impulse okay so the principle of impulse momentum what did it say is that that from Newton's second law the force acting is nothing but rate of change of momentum and so if you do this simple integration then what do we see that I've bar dT is equal to MV2 minus MV1 which is the momentum before the impulse was applied and the momentum after the impulse is over we saw yesterday that impulse typically just means the integral of force over a particular interval impact is a very special case of a impulse in which the duration is very short and within that short period very high forces act and as a result of which this integral even when T2 minus T1 which is delta T can be small but integral f dT can be very large and so there can be an appreciable change in the momentum of the particle note momentum when I say moment change in momentum of the particle I mean in the vectorial sense okay that the vector momentum can change appreciably we saw yesterday that we can also replace this moment this impact with the help of what is called as a mean impact force which is written as f bar and at f bar can be can also be written as integral f dT divided by delta T what is delta T is just T2 minus T1 so this can be said as this is a vector so vector never forget that f average okay so this can be said to be the mean force that acts on it now one thing which we noted that in the cases in the case of impact okay so there is one thing okay so there is a terminology that I have used is impact and impulse okay there was a question also asked on it okay so at least as far as this lecture is concerned the way we are using the word impact is that that the duration of the impact is very small but as we had seen in this yesterday's problem that impulse need not necessarily mean that delta T may be small it only means that even if a force is acting over a constant duration okay for example even if a force acts like this okay T1 T2 and the force may be a variable or it may be a constant like this the impulse is given simply by f dT from T1 to T2 and this is the definition of impulse and it is clearly a vector now we solved this problem yesterday briefly to find out what is the stoppage distance for the car now let us discuss another simple problem that a 120 gram baseball is pitched with a velocity of 24 meters per second okay baseball why example from beer and Johnston 10 American book baseball not cricket so 120 gram baseball is pitched with a velocity of 24 meter per second so what do we know we know the initial momentum of this ball the vectorial direction it comes here after the ball is hit with the bat it has a velocity of 36 meter per second in a direction as shown so you can see that this is 24 in the horizontal direction in words this is 36 at an angle of 40 degrees with respect to horizontal we are also told that if the bat and ball are in contact for 0.015 seconds this determine the average impulse you force exert exerted by the ball during the impact now the speed is given here okay so very simple problem so this initial velocity is given to us so initial momentum is known final velocity is known to us because the mass is also known the final momentum is also known to us now what do we want to do we just simply use the moment the impulse momentum theorem what do we know that the initial momentum plus this impulse okay to take it from 1 to 2 okay that that the impulse starts okay when the ball is hit with velocity v1 and the impulse is over because the contact is lost when the particle again goes along this direction okay with the velocity v2 okay now the x component we can we can rewrite this in terms of components we can rewrite the x equation we can say that our x axis is in the horizontal direction okay wide axis in the vertical direction so in terms of these components what do we have the momentum will be minus mv1 will be the initial momentum okay in the x axis x axis it is only mv1 there is no y component for the initial velocity times average force fx what we had discussed earlier the average impulse force fx into delta t which was a duration of impulse will be the x component of the final momentum okay this is simply the impulse momentum theorem what is that it is mv2 cos 4t cos of this angle so substitute all the values and we will see that the average impulse force was equal to 412.6 Newtons okay now writing down okay the component equation okay in the y direction what do we see that the initial momentum in the y direction is 0 f y is the mean impact force in the y direction into delta t will be equal to the final moment okay the final momentum in the y direction so 0 plus f5 d delta t is equal to mv2 sin 4t solve this and we find out what is the average impact force in the y direction and so ultimately the vectorial impact force is given by this we can just do square root of 413 square plus a 180 5.1 square and this will be the total average impact force that acts on the particle okay so very crude estimate of the impact force because typically the impact forces reaches very high at the peak of the contact okay and then drops down now this is a nice problem so what we have in this problem is as follows a 10 kg package drops from a shoot into a 45 kg cart with a velocity of 3 meter per second so this is a slope this is a cart okay which is used to carry this now what is done is that this particle slides over this and before getting rid of this contact okay before get before losing touch with the shoot what it does is that that it slides off clearly at an angle of 30 degrees the same as the angle of the shoot just when it is leaving okay and then what happens is that when that happens it has a velocity of 3 meters per second and it hits into this 24 kg cart with a velocity of 3 meters per second okay that same velocity at this angle it hits the cart now knowing that the cart is initially at rest and can roll freely okay determine the final velocity of the cart and impulse exerted by the car on the package and third the fraction of the initial energy lost on the impact now the deal is this so we ask ourselves that what are the various forces acting on this system so for example let us take the example of this cart for this cart there are clearly two forces acting one is the weight okay W and other is a normal reaction from the surface because the cart can roll freely okay it is given in the problem we neglect the friction that can be exerted by this surface on the wheels okay because the cart is free to roll freely now the second portion is that we are asked to if you look at this particle okay or this package which we are this package which is traveling at a 3 meter at 3 meters per second then what are the forces acting on it the force that will act on it is 4 due to gravity okay and and that and that's it before the impact happens okay that will be the force that acts on it but now we make a very small assumption okay that by the time the impact happens and this particle settles down so we know from our example what happens is that this will hit okay there will be a lot of vibration set in this car and this and this package will settle down and both of them will start moving with a common velocity okay in this direction so ultimately what happens is that even though gravity force of gravity acts on it okay before the impact also after the impact also okay during the impact because gravitational pull acts in the vertical direction okay we don't write that in the equation of momentum balance that we use for in the horizontal direction so with this metaphor preamble let us see how do we apply the principle of impulse and momentum to the package card now what happens is this that when this hits the card what happens that what are the forces acting on this complete system that this is the initial velocity when it hits okay this will hit it and come to rest in this position now during the duration when the hitting is happening what will happen there will be some impact okay there will be some impulse that will act on it okay in the horizontal direction and in the vertical direction and similarly on the card okay from the ground okay to keep this thing in balance because this cannot move in the vertical direction so there cannot be any change of momentum for this card as a result there can be an impulse that can act from the ground on this but now what we realize is this that as far as the x direction is concerned okay as far as the x direction is concerned what do we see okay we see that the total momentum of this system will be what mp v1 bar okay this is the packet the mass of the packet into the velocity of the packet okay this is the initial momentum of the entire system plus the impulse okay that acts externally on the system because note that between this point and this point there is an impulse but this impulse acting on the package and the impulse acting on the card they cancel out so if we take this entire system as one package okay as one complete system that the package plus the card as one complete system then the the impulses that act here they will cancel out but what do we know is that at mp v1 plus the external impulse acting which is this impulse will be equal to that when this settles down this will be the common velocity for both of them and so mp plus m car okay into v2 will be the final momentum for this complete say a cart and package now what we realize is that that it is very tricky to write down impulse momentum in the vertical direction because this is also unknown but what we realize is that that externally there are no external impulses no external forces acting on this system in the horizontal direction and because of that what we do is that we just break this component so the impulse component in the horizontal direction or in the x direction becomes 0 so mp v1 x what is v1 x v1 x will be just v1 cos 30 will be equal to mass of the package plus mass of the card into v2 just substitute all these components and what we will see is that the combined velocity of this entire assembly which is the package plus the card will be equal to 0.742 now we ask ourselves okay if we apply the same principle just to the package just to determine what is the impulse that is exerted on it from the change of momentum then what we see is that that this is the package this is the vertical component of the impulse force what is this vertical component of the impulse force that between this cart and the package there is an impulse force that act so it has a vertical component it has a horizontal component initial momentum final momentum so what this impulse do that this impulse essentially changes this momentum from the initial to the final you may ask me that we have neglected the weight from the gravity. Because why? Because weight is also acting on this system for a period of delta t. But note as we had noticed earlier, we will see that this force, this force that will come out, this impulse component will be far more than the component of the weight of the packet. So, that is why we neglected, but in principle we should also incorporate the weight of the package. We have said here, we have assumed here that the weight component acts for a very short time and overall weight is much smaller than the impulse components, which is this f x and f y. So, that is why we are neglecting it. Now, what is the x component? The momentum in the horizontal direction plus the impulse in the positive direction acting on it is what? f x delta t will be the final momentum in the x direction just for this particle. But now, by solving this composite system, we have found out what is the velocity of this composite system, which is also the velocity for the package and so, we substitute all the values inside. And what do we see that f x delta t will be 18.56 Newton per second. And similarly, we solve this and what we will see in the y direction when we solve this problem, what do we know that m p v 1 into sin 30 minus y, because that is the y component acting in the downward direction plus f y delta t is the overall impulse. So, the mean impulse in the y direction into delta t is the overall impulse acting on this package in the y direction is equal to 0. So, substitute both these values and we will see that the x component of impulse is acting as expected in the minus x direction and y component acts in the vertical direction. And what we have seen is that this is the total impulse that acts on the particle or that acts on this package. Then the last question is that we want to find out what is the fraction of the energy loss. We know the initial kinetic energy. The initial kinetic energy is given by half m p, p is the velocity of the package v 1 square, substituted it is 45 joules. But when the package hits and complete assembly now moves together the cart and the package they move together with the velocity v 2, which we found earlier from the momentum balance of this composite system in the x direction. Because for this composite system, there was no external impulse acting in the horizontal direction. So, we found out that v 2 and now what do we do? At t 1 or the initial kinetic energy simply this initial velocity is known. Final velocity for the entire assembly is known. So, that kinetic energy is half mass plus of the package plus the mass of the cart into v 2 square and you will see that the final energy is much lower than the initial energy. So, what has happened? So, simply for example, what has happened is that when this package hits the cart you will see that for example, lot of vibrations are set up in the package. Some part of the energy goes into setting up those vibrations. There is some plastic deformation both for the cart and there would also be some local deformation for the package that will also end up in dissipating the energy. Also some part of the energy it gets dissipated into sound and all those dissipation put in together even though the momentum is conserved in the horizontal x direction for the complete system the total energy for the system is clearly not conserved. And also that this part of the momentum is completely destroyed why because this hits it and gets stopped here and when it hits here a majority as we just discussed of the energy gets dissipated in the vibrations that are set up in the cart. Now, the next concept which I want to briefly discuss is the concept of impact of two particles. So, this is something where for example the case we discussed earlier was also case of an impact but here we will specifically discuss that when two particles collide with each other then what happens during that impact. So, let us define a few terminology. So, the way we define impact of these two particles is collision between two bodies which occur during a small time interval and during which the bodies exert large forces on each other. Now, the main terminology is that what is the line of impact? The line of impact is when these two surfaces hit with respect to each other in the previous problem we did not really clearly define what is the line of impact but here we define it why because the surfaces have a clear cut geometry and their normals are well defined you can define tangents and normal on the surface. So, we can clearly define what is called as the line of impact. What is the line of impact is the common normal to the two surfaces of contact during the impact. So, two spheres for example interacting with each other this is the common normal and this is the line of impact. Now, central impact what does that mean central impact means impact for which mass centers of the two bodies lie along the line of the impact that is another thing that we are going to deal with that the two centers essentially lie along the line of the impact. Ultimately direct impact is the impact for which the velocities of the two bodies are directed along the line of impact. So, this is a direct impact that the velocities are also directed along this line of impact or the or also the line connecting the two centers of the small particles whereas in an oblique impact what can happen is that that one particle has a velocity in this direction other has a velocity in this direction even though when they impact with each other there is a well defined normal. So, there is a well defined line of impact and this is also a center impact why because the centers of these two spheres lie on the straight on the line which is also the line of impact but the velocities are not directed along the line of the impact. So, these are the various impact parameters. So, first briefly let us look at what is direct central impact. So, what is direct central impact that the line of the impact and the velocities are in the straight line they are all directed in the same along the same line. So, what we say is that upon impact the body undergo a period of deformation during which the bodies are contact with each other and move with a common velocity. So, these two spheres they come together hit they keep moving moving till the bodies deform to their maximum it is a very small deformation that happen in those contacting spheres and then they start separating from each other and then completely lose contact then they start moving separately again. So, this is the overall impact procedure. So, this is called as a period of restitution. So, one is a period of deformation in which the bodies come they keep going going going deformation happen and the period of restitution is what that they start losing their contact and then they completely lose contact. So, the time during which the deformation the contact is being formed is called as a period of deformation and the time between during which from the maximum deformation to complete loss of contact is called as a period of restitution. So, these are bunch of terminologies if you wish to you can have a look at BJ 10 for example and just go through a terminology. There is bunch of terminology why I am using this because I need to use this when I go to what is called as the coefficient of restitution. Now, clearly in this case if you look at these two particles there will be some impulse acting here some impulse acting on this phase and ultimately what we realize is that the total momentum has to be conserved because there is no external force acting on this other than the impulsive force and the impulsive force okay it cancels off for this particle and this particle why because impulsive force exerted by A on B and by B on A are exactly equal and opposite to each other. So, then the conservation of momentum then says that M A V A plus M B V B is equal to M A V B prime plus M B V B prime okay if velocities along the right direction this is positive is velocities in the left direction this is negative. Now note one thing if I want if I know initial V A I know initial V B I want to find out what is final V A and what is okay this should be M just note there is one change this should be M A V A prime okay there is a mistake here. So, the second relation is required why because we have two unknowns we have velocity as the unknown okay initial velocity is given but the velocity final velocity of particle A and final velocity of particle B are both unknowns and we need an additional relation and that additional relation is provided what is called as the coefficient of restitution and the way we define the coefficient of restitution is as follows. So, look at this sphere okay let us zoom only on sphere A and not on sphere B okay we will zoom on that sphere later. So, when you zoom on sphere A sphere A keeps coming okay with velocity with velocity V A keeps coming coming it hits with the second sphere now what happens when sphere B hits sphere A it starts the both of them start deforming because they want to go into each other okay but because okay because of the the overall rigidity or overall elasticity of the entire material they cannot interpenetrate each other. So, they keep on deforming each other. So, first phase is that that if we zoom only on the sphere okay let us not concentrate on the other sphere then there is a impulse that keeps acting on it keeps acting keep acting till it deforms the second sphere to its maximum and the period between which the contact has just happened and when the maximum deformation has happened for either of the spheres that is called as the okay period of deformation. So, what we realize in this period is that just note the signs. So, M A V A minus this impulse P D T during what duration during the period of deformation okay will be equal to M A into U what is this M A into U that when it keeps hitting the particle the particle or the ball is still moving. So, till that period of deformation happened what is the that initial is when before the contact happens the initial momentum is M A V A till the deformation happens the intermediate momentum it has is some M A times U okay. So, this is the period of deformation. Now what happens is that the maximum deformation of one sphere has happened and now the sphere okay start to go back to the original shape and that particular period as we just discussed is called as a period of restitution in that what happens the shape which was kind of deformed slowly starts going back to some final shape. Now if the impact is perfectly elastic the sphere will completely recover its original shape but many times for example there is a permanent deformation that happens in the sphere and so after the contact is lost you will see that there is a rest there is a impulse which acts in this restitution period impact slowly slowly slowly the impact starts decreasing but the overall impact during that period of restitution is given by integral R okay R for restitution dt but the final momentum of that is what that this momentum in the intermediate period plus this impulse okay which is the in the period of restitution which will be the final momentum which this body A will have after the contact is lost so just during the contact deformation deformation that is the period of deformation starts slowly the recovery which is the period of restitution lose contact and whatever velocity you get now is the final momentum and the coefficient of restitution is defined in this way okay this is a highly empirical definition so you may ask me what is the basis behind it there is a very simple basis behind it is that that if this that if the if the collision is perfectly elastic okay that's a simple logic behind it the collision is perfectly elastic then what happens then the then the whatever deformation you get during the period of deformation okay you recover back deformation fully okay everything happens reversibly like the spring the spring skids getting compressed and when the particle starts to come out the spring again come back to their original position so that is a perfectly elastic response deformation and restitution are exactly equivalent to each other okay now in that case okay what we also expect is that for example in the case of spring the overall forces that keep acting during deformation of the spring or also the overall forces okay and the overall time that acts when the particle for example loses contact with the spring so taking that example is in mind we say that this rdt is the restituting impulse PDT is the deforming impulse and these two impulse for example the ratio of them we call as a coefficient of restitution now if this ratio is equal to 1 then what do we realize is that that if this ratio is 1 then there is a perfect the restitution deformation are exactly equivalent to each other and so this will become 1 and if that there is no restitution at all you hit it the deformation stays then this impulse becomes 0 only deformation no elastic rebound at all this is perfectly plastic deformation in that case this coefficient of restitution becomes 0 so it's a highly empirical concept okay it is not exact but in engineering mechanics and for many many engineering problems okay very simple engineering problems okay this to the first order or as a first cut is a very decent thing to do for this collision impact problems now we just take the ratio of this we can immediately see that this will become u minus va prime va minus u the same thing can be done for now particle B and what you will realize is that that coefficient of restitution will again be equal to vb prime minus u and u minus vb you may ask that why I have used the same u think about it that when the particles keep deforming ultimately when the maximum deformation has happened both of them okay will keep moving okay in the same direction with the same momentum why because if they don't then it means that there is still some relative velocity between them and the deformation can keep happening so this u will be the same okay at the end of the period of deformation for both particle A and particle B you just divide one with the other and what will we get is that vb prime minus va prime okay both directions of vb are along the positive x direction so vb prime minus va prime will be equal to e times va minus vb that is the additional equation we have in in addition to what is the initial equation for momentum balance or momentum conservation and you will see that this we have two equations to unknowns and we can find out what are the final velocities of both A and B if initial velocities are given now for a perfectly elastic impact is equal to 1 and you can also show that when e is equal to 1 then the kinetic energy is also conserved there is absolutely no dissipation and in a perfectly plastic impact e is equal to 0 and you will see that there is significant of amount of dissipation means the initial kinetic energy of the system will not be the same it will be lower than the finite kinetic energy of the system now we will not go into the details of that but the same thing can be done for oblique impact problems oblique impact means the particles don't impact along the line of impact but the impact like this but it is still a central impact problem what is central impact again that there is a well-defined normal and impulse forces act only along the line of impact so in that case what we can do is that we can write the impulse momentum equation okay we can write the impulse momentum equation in the x and y direction first we realize is that because there is no impulse in this tangential direction okay the the velocities of these particles in the tangential direction will not change at all okay that v a tangential will be equal to v prime a tangential okay even after the impact why clearly because there is in this assumption of central impact the impulse acts only along the line line of impact there is no impulse component in the direction perpendicular to the line of impact or the t direction and so if you resolve the components of the momentum in that direction you will see that the impulse momentum theorem will tell you that there the velocity the momentum in the vertical or the tangential direction remains the same and as a result this momentum remain the same but we can apply the principle of conservation of momentum along the line of impact and again we can also apply this principle of restitution okay for the component of velocity or the component of momentum along the line of impact okay and then solve these problems why because these two components are found out the only components that are unknown here is that at the final components along this n direction of a and b but we have one equation which is the conservation of momentum and other equation which is this conservation of which is this the coefficient of restitution equation and two equation two unknowns we can solve for the the velocity after the impact both for particle a and for particle b okay so we won't go into the details of the exact same thing okay if you if this particle is hitting an oblique block you can have a look in Beren Johnston okay about this now typically in problems involving energy and momentum okay these are some simple tips that we can follow that for example if you ask a question that we release this mass a from the top okay of this pin point okay this this bob is connected to the hip to the hinge by a string we take it upstairs release it and then you want to know for example what is the final condition of this entire system then what do we do to find out what is the velocity the velocity is zero here to find out what is the velocity here we apply conservation of energy we come here then at this point okay we apply conservation of momentum we apply the coefficient of restitution and from that we can find out that what are the final tangential velocities here and here and after we know that then we can again use conservation of energy to find out what is the final part of this two balls or of these two two particles now we will solve one simple problem okay before taking questions so what is given to us is that that a ball is to thrown against a friction less vertical wall now why do I say friction less we say friction less because okay let me draw a quick figure here so this is one thing which I want to emphasize in this impact momentum problems what we had said okay I am drawing this very big for exaggeration exagerative purposes this is the line of impact suppose this is the initial velocity of particle a this is the initial velocity of particle b mass is ma mass is mb vb now this is the line of impact this is the normal these are the centers okay now what we say is that when the impact happens the assumption is that that this is the impulse that acts on this particle a and by Newton's third law and equal and opposite impulse act on particle b and when we say we are neglecting friction in principle there can also be an impulse in the tangential direction and equal and opposite impulse acting on this in the tangential direction so in these kind of problems central impact problems this component we say that there is no friction between these two okay that's an idealization which is strictly not true but as a first cut if that if that if the dimensions of the ball are small okay so whatever the angular momentum components that will be involved are very small compared to the linear momentum components then we can neglect that so what we say is that this component is neglected and that's what we are doing here we say that there is no friction between them why because these components are essentially equivalent to the friction forces these are the normal forces the tangential forces are friction forces and we are neglecting them and what we say here is that this is the initial velocity this ball hits this wall no friction so the only impulse acts along this direction this is the final momentum and we are asked to find out that knowing that the coefficient of resolution is 0.9 determine the magnitude and the velocity of the ball as it rebounds from the wall now what do we do we resolve the component of velocity of the ball in the in the tangential direction and in the normal direction now note one thing that what do we know okay we know that vn will simply be equal to v cos 30 that is my initial velocity and vt or the tangential velocity will be just v sin 30 now straight away we can apply the principle of coefficient of restitution we say that this wall okay and it's perfectly fine to say that this wall has infinite mass so it will now have no velocity it has no velocity before the impact and after the impact also it will have no velocity so we directly apply the coefficient of restitution okay with the 0 wall and what do we see that 0 minus vn prime will be equal to e vn minus 0 just substitute all the values we will find out that the the final velocity in the normal direction will just be equal to this now how do we find out what is the velocity in the tangential direction we realize that because there is no friction between the ball and the wall there is no there is no impulse force acting on this in this direction and as a result or in the tangential direction the velocity or the momentum of the particle is conserved in this direction and so the velocity in the tangential direction also remains the same so with this simple problem okay we also saw how to incorporate coefficient of restitution there will be one or two problems which will deal with in the tutorial okay so there are some questions let us take those questions first question is by center 1 2 2 7 in sample problem 13.12 why impulse 1 2 is 0 okay so note one thing that this impulse 1 2 is not 0 okay so let me discuss this briefly so what is happening here is as follows if we look at the cart okay and this package during the impact process separately so first let's zoom on to the package what will we see we will see that this package has an impulse acting on it integral fx okay it has a component in the x direction it can also have a component in the y direction which is integral f y dt its initial before the impact started its initial momentum was mv px after the impact was done the final momentum was okay mp v2 all in the x direction okay now if you write down this entire thing even on the card what we will see is that that the cart will also have an impulse like this the equal and opposite impulse okay integral f y dt y from Newton's third law will act on the card and this another impulse equal and opposite to this will also act on the card now why should there be a impulse coming from the ground because if there is no impulse in the y direction coming from the ground what we will see is that the cart will have a momentum change in the vertical direction so there should be an equal and opposite moment impulse from the ground which can balance the card because the cart is free to is free to roll in the horizontal direction what we say is that that this impulse in the horizontal direction does not exist so for particle this is the impulse diagram for the cart which is this is the impulse diagram now if you put them together okay you put this and this together what will happen is that this internal impulse is plus minus cancel each other this plus minus cancel each other and what we are left with is the figure that is shown here so the internal impulses between the package and the card they cancel each other so we don't take that into account but note that this external impulse in the y direction also remain but what we have realized here is that that is external impulse as a component only in the y direction okay this has a component only in the y direction okay and not in the x direction so if we break down this vector equation in x and y components then along the x direction there is no external impulse so that's why we have taken that to be equal to 0 it is not that there is no impulse but along the x direction for the complete system there is no impulse there is a second question from center 1 0 6 0 when potential energy okay is equal to kinetic energy so this question okay let me answer it in one way so I can answer a very simple question like this we use the example of our below at pendulum we take this pendulum start here okay start here and what do we see that with respect to this reference line okay let us take that this length is l this length is l so from this datum the potential energy v 1 is equal to what v 1 will be equal to simply m g l now kinetic energy initially is equal to 0 and when the ball come here okay downwards what happens with respect to this datum v 2 is equal to 0 and kinetic energy t 2 will be equal to half m v square and in this case if we if you apply principle of conservation of energy assuming that there is no dissipation from any sources and this is equal to v 1 plus t 1 is equal to v 2 plus t 2 and in this case the entire component of potential energy will get converted to the kinetic energy so I hope this is okay then there are two different questions one is by center 1 1 5 7 they have asked please discuss the concept of force acting in the elevator or lift okay so I presume okay that this question is about the brief discussion we had yesterday about the concept question one so let us briefly discuss this let us say that we have an elevator which can either accelerate up okay all down now let us take a person who is standing inside this lift okay it may be us or anyone else now this lift is going up with acceleration a because this person has contact with the ground what happens his acceleration also has to be a now if we draw the free body diagram of this person okay then what are the forces acting on it the forces possibly it can act on the person okay so one force clearly is the weight mg second force will be a force okay normal reaction coming from the contact between the person and the elevator there can also be a sideways friction force f now we apply Newton's law on this this this entire system okay what do we see what we see is that now in principle you may say that there may also be a couple and so on okay so let us not worry about that for the time being the person is stable so its center of mass is directly below the reaction okay so let us not worry about the moment that acts from the force now writing equilibrium of equation in the y direction okay say this is x and this is y so writing equation of equilibrium in the y direction what do we see okay the sum of forces in the y direction is equal to n minus mg but what will this be equal to if the lift is moving up this will be equal to ma and then what do we see we see that the normal reaction will be more than the weight of the person now if the acceleration is negative or the acceleration is downwards then this will be equal to mg minus ma okay and so apparently the person will feel that the weight has little bit decreased as far as the contact with the ground is concerned okay so I hope this address is the question about the forces that act on the person doing the elevator


Beaver women also in action trying to avoid a sweep in Duluth. Second period, Beaver's down two. Alexis Joyce skates across the blue line, cuts back to the middle, and fires for the goal. BSU pulls within one. Later in the second, Beaver's down two again. But on the five on three, Emma Terrace fires the one-timer into the net. BSU pulls it within one. Same score in the third. Alexis Joyce here firing the wrist shot. It gets blocked, but there's Terrace again to clean up for her second goal. Ties it at three. Regulation wouldn't be enough. This one would go to a shootout. Laura Stalder beats Brittany Moet, glove side for the goal, for the game winner. This one officially ends in a tie three to three, but UMD wins the shootout, gets the extra point, one to nothing. If you've enjoyed this segment of Lakeland News, please consider making a tax-deductible contribution to Lakeland Public Television.


Hello. So as last time, we said we would not be waiting for anyone. Of course, we want to establish that things start on time. We will actually start on time. Let me just, I can't adhere the channel. Yes, Steve. So let's start. I have to admit this is the first time I'm actually coming in somewhat blank. Of course, I have meetings back to back 24-7. Toxic updates. We literally dropped off the call between TOC and SIG. The vote for Techlead will start officially today. Apparently, I had some formal mistake or whatever. I don't know. I thought we started this formally like a month ago, but whatever. We will be having the formal vote on Techlead starting today. Amy volunteered to fix whatever I did wrong. Super nice of her. I'm really happy for all the formal stuff. The other update is the due diligence of, sorry, there's one more. The TOC was concerned about the diversity level of the chairs. So they actually asked us to look for different nominations, which obviously is bad for Steve, who's also here. We reached out for both TOC and also behind the scenes, but anyone who wants to nominate someone or nominate themselves, speak up now or send email or focus on Slack or whatever. We are there. We are listening. So please, please focus. Now we're coming to due diligence updates for Cortex. There are some open questions which are currently being addressed for Thanos. All open questions have been addressed. So Thanos is moving to public comment phase. That thread is already on the TOC list. Everyone here is encouraged to also voice support if they want to voice support. It's ongoing. It's good. And feedback from TOC is basically that due diligence is good. They actually called out the Thanos doc. But just for anyone on this call, the Cortex and the Thanos docs are actually pretty much the same from the structure as an example of how to do a due diligence well, which is super nice. And I think Bartek deserves a shout out for driving the main brand of that work. So yeah, that's it. And else, I informed TOC that we are doing a little DCP doc and that we are doing the use cases for data analysis and we'll start working on this. Nice. I think one more thing I got from the call we had literally one hour ago was that CNCF is really encouraging seeks to use the CNCF block space. So we are welcome to produce any content we want relevant to our topic and this will be published in the CNCF blog post. So I think recently seek storage or something like that, expose something on the white paper. So we are encouraged to do that as well. What do folks think as an idea for a white paper or rather a blog to identify opportunities for new contributors to come join our second due stuff. I think we have a lot of like potential future ideas identified and in some cases we already have GitHub issues that are marked with, you know, good first time issue. I bet we can expand that a little bit just by going through the charter and blog about that sort of introducing this big scope and just a general call for contribution. That is a pretty good idea. I mean, we could definitely announce, you know, kind of seek a sort of written explain a little bit what we do there as well. Yeah, there was a blog that went up from, I think that you'll see a little while ago, a couple weeks ago, that caught me a little bit by surprise. So I didn't actually get a chance to respond before they printed it. But that was sort of from the outside in perhaps now it's time to do a blog from us to the broader community. I can check with CNCF if that's content which they would like to see. And if it's content which they would like to see, I can just start a doc and throw it in the channel. But I like the idea. It's a good idea. Because the inherent problem we have is most people who are here are here because they already actively watch what is happening within CNCF. Whereas the blog might be a chance to get coverage on the outside of CNCF as well. I suspect especially end users in such like most of them, not all of them as we see in this call, but most of the end users will not actively consume anything which is happening within CNCF in absolute inner workings. So we can spread this more. Is anyone interested in spearheading this? Or I will if nobody else wants to. But I'd rather contribute than drive it personally just so we can fan out. If no one else is volunteering, I can do it. I'm starting to get used to having all blog posts anyway. I would be overall interested. This is a mare. I would be interested in contributing to the blog post, I guess. You know, as a writer maybe in the beginning. Cool. So do we want to start it as a Google doc and just collaborate that way? Yep, as per usual. Yep, sounds good to me. Just a moment ago, I just set the action point before that actually to reach out to CNCF if they want to see this. By the way, everyone is more than welcome to also chip in on writing the meeting notes, which mainly unbox me for. So the next part of order, the topic is recommendations for OLAP system. And there are tons and tons of suggestions within that document. You actually have two documents now. Just a moment. Here are the use cases. Should we just start walking through the use cases to see what people like, what they dislike, and then just start accepting stuff? Okay. You can all see my screen, I guess. I probably need to resize to match a more normal screen later. Okay. Can I assume everyone has read this or should we walk through it slowly? I think there are literally last minute changes by Ivan or people literally, you know, two hours ago. Okay. So I'll just give everyone some time to read what's on the screen. I'll also resize some more. That's the problem with ultra whites. I don't have a concept of what other people's screen look like anymore. No, I'm in this with the wrong account. Bartek Matt, if you can add my work email or else I can close this window. Yeah, let me do that. Sorry, what? I just realized I can't. I can't. Yeah, I'm doing this, no worry. Recommendations. Should be now. Oh, I see. Now? Yep. Thank you. I suppose it's a little off topic, but do we have like the ability with CNCF to have a shared Google Drive just for our SIG so that we don't have this like... I can ask with my Prometheus head on this was a rather long process, but we needed, like with Prometheus, we needed probably different stuff. Yeah, let me take this as an action point. I can actually take this one. I've been a little bit between vacation and things a little bit, not here as much as I'd like to be. I can chase it down with Cheryl. And we have a service desk request I can make, I think. Yeah, you probably want eHor, but yeah, either works. Yeah, I'll take it. Okay, cool. I put it off topic. Okay, so the first edition is this one. My own opinion, it's valid. The only thing is, should we define strongly? I think it's somewhat obvious in as much as you want to carry the same metadata between the different things. And being someone who has argued for years that something like Logan needs to exist, I know where this is coming from, like you need to have the same metadata on all the things to make jumping between the different systems. Metric flow is easier. So I would tend to just accept as is or do we need to put verbiage of what strongly means? Maybe I can explain a bit more. What I would like to see is, and the problem we're facing right now is there is no way for us to relate all this thing together. Like you mentioned, there is no metadata for it. Locate didn't exist until very recently. And we cannot offer users even a single way to look at metrics, logs, traces, error reporting in a consistent way. And there's no single dashboard for all of those things. So it goes further than just anomaly detection. Having all this data together and accessible through a single view, for instance, would be a huge improvement. So I absolutely agree. I mean, I'm obviously biased working where I work, but yes, I agree with everything you said. I think for companies that take more of a, I don't know, a lot of people on this call are just super jazzed about the topic, but at the end of the day, time to remediate an issue, time to diagnose an issue, MTTR, MTTD, all that stuff. That's like real money. So I think this one in particular, this correlation and just the time it takes to do this manually without something like this is one of the bigger costs that makes it an opportunity and then something worthwhile chasing. I know we're not prioritizing, but if we were, this is the one that I see come up a lot. Yeah, no, it's a valid point. That's implicit in, I think, everything we said, but yes, it's probably good to make this explicit. So I would just accept this. I made this addition, but I don't think that's contentious. Three, two, one. Good. So data governance specific use cases. I think it's not really part of analysis. On the other hand, it is a valid point which will probably play into the end results. So I would tend to keep this in the question, is it not location specific? So maybe we can find a better place for it, but the statements in and as of themselves, I think a valid is even on the call. I looked through the attendees and I don't think so. Yeah, it looks like more like requirements in the same way. Hey, system should have this latency. That's kind of the same. Should be secure. Definitely worth remembering that. Not fully. This is a multi-tenancy sort of kind of issue also, right? And the one thing which is missing, no, it's absolutely multi-tenancy, which is a very valid point. And for example, delivery ignored with impermitence, but it's a problem which people have. In our case, it's a problem we have with lurking the first place. So we use elastic to cover that and it kind of sucks to not be able to switch over, for instance, just because multi-tenancies is kind of harder. Yeah, absolutely. Like multi-tenancy is one of the hardest things to put into a software if it's not there a day one. Of course, it basically flips everything within the data storage, which is usually one of the most painful things to touch. Okay, so I think we can accept this as valid use cases, but we need to find a different place for this. At least this one. So let's talk about... Just to be clear, as our goal here, just to quickly confirm that these are all valid use cases, but for stall discussion of either priority or extrapolation on the use case, or do we want to kind of go deep in this time today? No, the intention as per last week was to just collect use cases, get quick consensus on all use cases. Are they valid? Are they not valid? And we have quite some of them. To then in the next iteration, without needing to be interactive and in real time, basically comment on what that is. And that means obviously priority station, hybrid, and I'm going to actually... How can those use cases be solved? Awesome, thanks. So basically, here we just have... Is this valid? Do we agree? Do we need to be more specific, less specific, cover other things? Like for example, the MPDR comment or the multi-density comment. This is exactly the kind of honing the statements which we're looking for, and then just accept it and work based on this. What does this actually mean? Like for example, to have a specific example within Prometheus, multi-tenancy is deliberately ignored, but then it makes sense for... With my Prometheus head on, to get a challenge from CNCF or the wider community or whatever, what are you doing about multi-tenancy? And with my Prometheus head on, the answer is we deliberately ignore this for very good reasons, but then at least we make this more explicit. And I know with my Prometheus head on, we have this in our documentation as to why we do with this, blah, blah, blah, blah. But then it becomes a checkbox, and either we tick it or we say, well, we don't tick it for a reason X, which with my sick head on is, I think, absolutely valid that projects deliberately ignore use cases, but then we can say, okay, this project doesn't follow the use case, unless it's super high priority, and then maybe it becomes a hard requirement. But then the SIGs cannot directly impose any requirements onto member projects that was made very clear during the SIG creation process. Of course that's what actually it does. Okay, so it should be possible to extract a subset of data for specific use cases while keeping others protected. I don't know what to make of that statement. It seems to be a copy of this statement. So for this statement as currently marked, I would tend to delete it. Or am I missing something? Yeah, I think that's essentially multi-tenancy. Yes. Or to phrase it differently, extracting is just a specific case of accessing, so we can just kill it. Correct. Okay, cool. And this is what I just put in, because this is also something which will start to bite more and more data sovereignty laws. Like this data must not leave a certain jurisdiction. Singapore, China, European Union come to mind. This might be solved with just deploying in a different zone or something, but we should at least think about this going forward. So yeah, I would tend towards accepting those two then. Comments? Yes, no? I was just back, I wasn't sure about this, but I was assuming that this also meant things like EPHI or PII. PII is a very valid point. For health information like EPHI as well. Just to, can we accept those? And then we should jump directly to PII. Anyone against accepting those? Three to one? Good. Yes, PII is absolutely, I need to filter out PII. Yeah, and then the last kind of bucket of data sovereignty also, at least in the US, is the CCPA or the consumer protection stuff that wanted to affect where a consumer can say, you know, that shall delete all of my stuff. And this is a problem for many log aggregation, and that's another scenario that I see. Like all of these bucket and under this data sovereignty or data governance compliance. I mean, those two points or at least this here points towards needing mechanisms for rewriting the storage and such, where for example, Thanos has a really nice storage, whereas Prometheus and Cortex not yet so much. I mean, Cortex is getting there, Prometheus. It goes so far, but yeah, I think those are valid in those cases. I realized I added it, I didn't make suggestions, but should we add those? Anyone against it? Are these valid use cases? Very good. Let's just make this a heading one so we don't forget this. Oh, funny. I thought people would have thoughts around this, but it's probably self-explanatory, but what I meant with this one. Okay, Rob, are you on the call? I can't see the participant lists. Ah, here you can see it. No, he's not. So I think this one is a valid use case, but it's not really an atomic use case because it's basically just a vehicle for saying, I need to access lots of data, which is kind of the point what this whole analysis push is about, or am I missing something? I mean, this is doable right now at basic Prometheus queries, but if I assume and if I infer that they really mean on large sets of historical data, like over the last year or two years, like that, that gets to be more at least into this OLAP or analytics use case versus just a straightforward computer rate using metrics. Yeah, it looks like long-term storage essentially with the same kind of aggregate, well the same details across years and months, yeah. So this is all basically stats over queries over my years in a nutshell. If you want to sum it up in five words. It seems like I just don't want to delete it without Rob getting back to us. I mean, coming from, initially coming from, from the mainframe world, this concept of interactive queries versus batch queries where batch queries can just run in the background and I don't care when the result comes back, I just care that it comes back is probably something which also plays into here. The one thing that may be different here is that you might be aggregating over dimensions other than series ID, like promql. You can only aggregate over series ID, which matters for aggregates like median, where re-aggregating makes a big difference. So one of the things that I think is getting at here is aggregating over different dimensions than just series ID. That's a really good point, yeah. I didn't get the point, sorry. He's saying that one of the one of the harder things to do if I understand is to aggregate over things that are not series. So there are some aggregations that involve revisiting all of the data or reformulating it or, okay. Do you know, like outside of just the promql box where you can aggregate on series using that if you already either have other attributes that you want to aggregate on? For sub-attributes of the series, for example, getting a median grouped by the namespace is different than getting a median grouped by the entire series and then grouped by the namespace. Yeah, but you can do that all, you can do all of that with promql, no? Because you have different labels, different dimensions as part of the metric. As far as I understand from promql, your initial aggregate will always be on the series and then you could re-aggregate. But again, for some aggregates that doesn't give the same result as aggregating initially just on namespace. Yeah, so you can definitely do multiple aggregation layers and you can do that even across different periods of time if you have aggregations over time as well. This is kind of recently, like a year ago, thanks to sub-queries. So you can build totally kind of complex queries and you can totally mix whatever you want to median group and then have different aggregation grouping across different labels that are resulting from the initial grouping or things like that. Unless I'm missing, I think there is no limitation for that from promql. Sorry, what I mean is you can, in promql, you can get the median by series ID and then you could get the median by namespace. But getting the median by series ID and then median by namespace is different than getting the median by namespace to begin with and that you cannot do with promql. There's always an underlying lower level of aggregating by series. Maybe this isn't important, but for some types of analysis it actually ends up being important. Nice. Sounds like it would be awesome if you can provide some example like offline even here and then we can look at that. Kind of makes sense, yeah. Yeah, like say you're using like timescale or something like that so it's postgres underneath and you're remote writing metrics to it, right? You might, yeah. That's a good point. I'm happy to accept it and move on and just to take an action to write this up in more detail. If you want to do that directly, you seem to have the best handle on it. So to suggest us to basically also just like I'm obviously always torn with 20 different heads about how much to interject when we diverge in interesting discussions from the actual topic at hand, which is always super hard to juggle and any feedback as to how much leeway versus lip cracking people want is highly appreciated because I don't know how exactly people want to have it. Yeah, this one I think is a valid use case capacity plan and we can just accept as this of course. You can generalize a bit to trend analysis or predicting time series because it's not only about capacity planning any form of metric you'd like to predict what it's going to look like in for instance a year or in a month. It doesn't have to be just how much can I do to scale my cluster in a year. I agree with the sentiment expressed absolutely and that's precisely what this talk is about for the use case. I think this is already a valid use case. I mean we can start deleting words like for example it doesn't matter if it's a Kubernetes cluster it's just whatever work environment you have on the other hand having examples is not bad either. Yeah, there is an I'm saying that is I think below there is another comment from Ivan or suggestion from Ivan about pretty much the same thing. You want to do prediction of what you need to do later on. Let me see if I can find it. Oh yeah, you mean this one? Yeah, exactly. Yeah, I had written a similar one too. There's a prom-con talk from Munich last year. They kept really from GitLab about this talk. Yes, we can already start condensing this down. This makes sense but also when we come to here we can just start removing stuff. No, it makes sense. It can be even wider. I think this is suitably generic. I think I can only accept the whole thing as one. I had to accept it but I'll just mark it as such as something which is under discussion. Yeah, we'll have to dedupe later and call as multiple passes. This one as marked probably maybe we can rephrase it like this. I think this covers the intention and also goes with should the comment is gone because I accepted stuff. Okay and I would actually say that we can move this one to here. Everyone agree? I need to learn to ask if anyone disagrees. So anyone disagree? Three to one? Also looking at the time we maybe have like five minutes more and then we need to flip over to the next topic or we decide as a group to stay with this document. Okay, all of these are valid but they are not actually use cases. So maybe we can put this into a consideration section or an example section. So if we put this, if we phrase it like this, is everyone okay with this? Anyone disagree that we like this or maybe for context this is this is one of the tricks from from ITF where you have the actual intention of the document and cover this in this case use cases but then you just have a consideration section which basically allows you to put noncore stuff into the same document while clearly keeping this distinction between about you actually want to talk about versus what is good to keep in mind. So I would tend towards doing it similarly here where we can where we can have a thing at the end to put considerations and examples. Yeah makes sense. I like it. Anyone disagree? Okay let's just okay I'll just accept everything and we just walk through it because as I kind of flip did anyone see if I closed any comments? I think I only accepted edit and I hope I didn't close any comments. No I didn't close anything. Thank you. Okay this one we can kill because we we have that so how can we phrase this as a use case? I think it's valid but isn't that anomaly detection again? It kind of is which is like I think honestly anomaly detection is largely out of scope for this effort for the simple reason that if your dataset is large enough you will always have correlations. So you would need actually domain specific things which which can look at stuff and optimize and those things are usually human of course machines depend on pre-tagged data even in cutting-edge machine learning you still need humans to tag data so all of this is a complicated way of saying if you do just pattern detection and anomaly detection you will always find the wrong stuff. Well yes it suggests to use root cause analysis in the chats. So to flip this into into a use case which involves the human? Well true but you know there might be systems that allows easy definition of how anomaly detection should be run and you know if you can at least create some integration that will pull this data from where you want and this will be defined by humans this is already part of the system to to make that to allow that right to define the API that would satisfy this need so this is still kind of body-to-use case to me. I'm not saying it's not valid I'm just saying we need to flip this and for the generic machine learning use case I'm not convinced this will this will work anytime soon but yeah so how can we flip this into a use case? Is this something which covers all intended meanings of what we talked about? Yeah I think it covers it because if you look at the second bullet points below there's something like for instance symptoms versus versions of software and you could have a human saying well for this version we expect this for this new version we expect that and suddenly we don't have this normal state anymore. That's kind of practically what you what you wrote in the end. Okay but this would be covered by this? That's what the second bullet point hints at least. Yes yes I mean yeah yes but yeah and sorry let me restart the sentence my point is I'm trying to reduce text as much as possible as per usual of course writing more text is easier than writing less text so I want to really condense into atomic use cases and then we can start exploding from there again. So the question I think which I was trying to ask is is this covering everything in here or did I miss anything? Because this one and this one like these two are to me basically the same thing just traced differently and by extension these examples fit here at least that was my thinking but I might be wrong. So if I look at the next one there is also a question of integration with things that are not observability related for instance there is a mention of ETCD but you can imagine that it could be anything that's not Prometheus, Sieger, Loki and so on. Yeah this one would be going into this section I think that's more this system or just this type of problem. Okay so to close this mentally this one I can I can delete everything because it's covered by the sentence above correct does anyone disagree and you're more than welcome to disagree I actively encourage you to disagree of course again I might just be wrong. I think it's not only detecting anomalies it's also correlating the causes for those anomalies like the problem is it does not to detect the anomalies also to say I've detected X anomalies and they are all on this specific software version which I don't think the sentence covers. Maybe just detect the anomalies and their causes in an automated fashion. I'm not convinced you can detect the cause. Maybe symptoms rather than causes. Yeah correlation and causation are like. But then we can just replace anomalies with symptoms of course basically anomalies is so I'm not convinced we can actually detect the root cause automatically because this this presumes encoding everything into the system and I don't think we as a field are at that point we can. I'm making an unrelated remark though because on the agenda there are still 11 minutes of topics and there's four left. Thank you very much very very much let me check guidelines for new metrics and list of projects landscape document okay so should we leave off here and actually try to condense this down into use cases because these are more like these are literally bullet points not atomic use cases so let's do it like this. Anything below the axis is not or in between the axis has not been. That's cool that's our grooming line and once again thank you for calling out the time I didn't catch who it was but thank you very much. Yeah so Arthur are you are you with us? If not I can kind of introduce this topic Arthur. Yes I am but I would prefer if you could. Essentially looks like you are looking for kind of information regarding the observability and this is actually the topic that well we should be responsible for and we have like CNCF project flags which are looking into increasing improving observability overall and you had a couple of questions and those questions are like totally valid and and I think we are missing some I don't know good guides and maybe tutorials that will be giving you this answer immediately. I think I answered everything you can kind of check like below however what I would try to kind of talk about during this meeting is how we can make sure you would be answered without our help but with I don't know some content that we provide right so my question would be for you Arthur what were the sources that you were trying to read before this question did you try to reach I don't know did you look on any videos or any any because you had some knowledge before that I could see. I have some previous knowledge because I have been working for me just for quite some time but this is the first time I'm implementing a new matrix. I've tried looking for any guides on Google, CNCF repositories but really I couldn't find anything. Can I ask her a question maybe because this is specifically talking about metrics but isn't the issue also broader than that in the sense that observability guidelines are not really there how do you implement tracing or logging for a service for instance in a way that's actually useful. I totally agree because flux problems is not only with metrics it's observability everything related to it tracing events logging everything you just said. Exactly and I think you just started with metrics as the first thing but the plan is to go forward right with flux. Anyway from in my opinion like we already have topic around working group for blog posts or videos or even white papers so those questions are are definitely giving some kind of direction that we should follow and I don't know do you have any today to the kind of CNCF seek team do you have any suggestions how we could take it and make it actionable something from it? It's the first thing that come to my mind on the beginning of this meeting someone said about the CNCF blog official blog could be this a good place to start with. Yeah that makes sense from my side however this is very like one of things that we could write and it will be just you know forgotten after some time so generally it would be nice to have some kind of yeah Viki or some kind of space that someone can yeah some kind of index of knowledge right this is what seek observability could try to maintain I would say to have like a starting page for those kind of observability features for like CNCF application right and then you know for metrics you go there for logs you go there and like I would say something more discoverable than blog posts but the blog post is better than I think yes. Now a few places of documentation in official projects if you look at Prometheus there is like best practices into how to create observability and metrics into your to your service but it's not enough or it's very specific to metrics and that's not the only bits that you want to show. But that's a good point because you're right that each project has its own documentation that is that is growing so it would be nice if this feedback you know we can be an entry point as a seek observability and then we can forward this feedback to the project and improve their kind of documentation however we should be kind of a starting point which means we should first even forward those people to those projects documentation but that's yeah that's very good point because you like your questions like they the answer for those should definitely be part of the Prometheus doc right. So that's fine when we have questions around this where I'm working we always refer to the Prometheus documentation when considering metrics because a lot of those questions are actually answered already it's just they suffer either from a discoverability problem or the people just don't immediately think about okay how can I like figure this out on my own. I think within the six space having and I think Bartek was looking for BCP's best current practices as this knowledge base of what is currently the thing to do or to suggest something like I'm not sure if it makes sense for for Prometheus and others to basically refer back to a shared documentation that has its pros and cons there is also and I know that I'm the one telling on that one open metrics is finally making actual good progress and we have tons of considerations in there as well about how to do this and those are already seen for example in open metrics and open telemetry at least to some extent blah blah blah blah so I think having this is good but there is already ample pre-existing knowledge which should probably be reused and then we can just take the same thing make it as a blog post make it as a bcp and basically use the same thing twice and get trusty coverage. I do miss some sort of a white paper describing what would be best to implement like people are talking about golden signals or you guys should have service level indicators that's very hard for newcomers to say this is interesting and you should expose it. Okay so looking at the time what are the next steps here should that be based on on what we have within other projects IG, e.g. Prometheus so we can so we can get this into a publisher forum or what are the next steps here? Well I would say entry point would be would be next step I think Arthur got we can help Arthur like in the meantime in this issue but entry point with maybe what Arthur asked about is a good starting point for entry point so entry point would be some index page whatever in our repo maybe it's a good idea okay so something that Michael is adding right now okay yeah I'm happy to start that yeah for free to decline or edit or approve whatever this is just free notes I think this is what we want is that is that right are we agree with entry point for like index to other projects documentations that are kind of official it also ties nicely with the next point on the agenda which is the landscape list of projects thing yeah I agree cool I think this is a good next step and we have like four minutes for a list of projects actually we have 55 minute meetings but yes let's take some some needs to run um let me pull up the next one so I think Bartek you want to take this one correct actually I can stop I guess Bartek yes no yeah sorry I didn't put that on agenda I was muted oh I thought you put it there sorry I can talk about that I can at least give a context about the issue I created initially about the list of projects I thought we can add a nice kind of overview of the kind of into the light landscape which is kind of interactive this landscape map if we can have some kind of filter based on the seek relation and looks like Dan kind of pointed me that there is observability and analysis kind of topic so you can filter by that and I kind of I think we we changed our repo even to to to give this link and it might be good enough that was the latest kind of news on this topic so there is still there there's nothing for a seek relation but there is like topic that is kind of related to us like one to one and yeah I can I can give the the link as well so whoever put that topic on the agenda um question is is that fulfilling it or yeah what are the next steps you mean you mean adding this to all the other things in the landscape sorry you mean you mean adding this information to all to all the things um you can just PR it I think I added but yes correct um the the other question is is this really what we want and is there anything missing because some of them are incubation some of them yeah I think this is kind of highlighted and you can filter by that so the questions isn't up to date I'm missing something in it where basically it says monitoring logging tracing and then chaos engineering but maybe monitoring is a big category right now I think you can split that further into metrics tracing I'm pretty sure um there are things that are a mix of those as well so it's not exactly black and white either on the on those categories either yes I'm thinking about a vector for instance which can do metrics and logging at the same time correct and open telemetry is tracing even though it's also other stuff right yeah exactly that's a body point for the feedback for this landscape I guess however we can totally use that I'm pretty sure okay I will add PR if it's not there to mention this and um sorry what's your name again um Michael Michael can you just put an issue like comment on an issue maybe um about this feedback or even start an issue on the landscape if you can do that that would be so awesome because this is an issue on this landscape that you know this is not entirely true what if the projects have shared shared topic let's say yeah I'll open an issue on the landscape awesome go on we're over time anyway and we're through sorry for not catching for not catching um we're at the working dock early enough and thanks again for for catching me I mean to to put it to other stuff okay um I highly encourage any everyone to to keep working on the on the OLAB document so we can just rather stand with the next time ideally yeah awesome thank you thanks bye bye


Ladies and gentlemen, thank you for coming. I'm going to pass the floor to WIPA Director General Francis Gurry to talk to you about the international patent system in 2010. And our Chief Economist, Karsten Finke, is also with us today. Thank you, gentlemen. Thank you, some ladies and gentlemen. Very good afternoon to you all. I think it's the first time we see each other this year. So I'm very belatedly a very happy new year to you all and a happy year of the rabbit also to Chinese new year. Look, I think we have a very simple story to tell here. It's not very complicated. And it's clearly set out, I hope, in our press release. I think the salient elements of it are, first of all, that, yes, we have seen the recovery, the technological recovery, if you like, in the international patent system. Because overall, across the year, we have had growth of 4.8% over 2009. But the qualification, if you put that in a broader historical context, that only takes us nearly to the level that we were at in 2008. So in other words, the impact of the crisis has been quite severe. Two years on, at the end of 2010, we are only just approaching the level that we were at in 2008. The good news part of it, however, is, of course, that the arrow is, for the moment, pointing very much in the right direction. And it's up on 2009. So that, I think, is the first thing to note. The second thing that I would note is to repeat the, I think, the story that we have been giving you for five years now, that there is an enormous geographical change in the international patent system. And in particular, we see a meteoric rise of Northeast Asia, Japan, China, and the Republic of Korea. Japan, to a lesser extent, because it is more mature technologically, so the growth rates are smaller. But nevertheless, note that the growth rate for Japan of international patent applications last year was 8%, 7.9%. And that is a very significant growth rate when you compare the performance of the rest of the so-called industrialized world. It's a very significant increase. The growth rate for the Republic of Korea was 20.5%. And again, for a reasonably mature technologically-speaking country, that's a very significant growth rate. And the growth rate from China was an astonishing 56.2%. And an astonishing 56.2% because it's a growth rate that comes on a base that was larger than the base of France or the United Kingdom, marginally larger. But it was marginally larger in 2009, but now significantly larger. So that is really quite a significant, I think, continuation of a story that we have been telling now for five years, I'd say.  And you notice the one thing to notice is that China has moved into fourth place, overtaking the Republic of Korea despite the very high growth rate in the Republic of Korea also. And so again, you see that there are three Asian countries, three Northeast Asian countries more specifically that are in the first five. It's US, Japan, Germany, China, Republic of Korea. So this trend that we've seen is reinforced. It's very much present there. If you were to go, then, if I may point you in the direction of page 5 and table 3, we set out the top applicants for international patent applications. And again, I would just point out to you that six of the top 10 are from Northeast Asia. So three of them are from Japan. Two of them are from China. And one of them is from the Republic of Korea. The other four in the top 10, three of them come from Europe. And one of them comes from the United States. I suppose a third point that I would make to you is the poor performance of the United States of America. And if you were to look at the table on page 3, you will see that in 2010, the number went down by 1.7%. But if you look across a five-year period, you see that the US is still very much below the place where it was in 2006 or very much below the place where it was in 2007, roughly 20% below where it was in 2007. So this is, I think, a significant indication of the impact of the crisis. The last thing that I will say is just to draw your attention to a relatively new feature. And that is on page 7, where we have set out the top university applicants for international patent applications under the PCT. And the first four are the University of California, MIT, Texas, and Florida. You will see that this table is dominated by American universities, which reflects, I think, the strength of the American university system. And also the early adoption of technology management programs by American universities. Nevertheless, you see that Japan has improved in this table of commercialization. And as far as Japan is concerned, the number of Japanese universities in the top 50 moved from six in 2009 to 10 in 2010. But the table of the top 50 is dominated, if I'm not mistaken, or composed exclusively if I'm not mistaken of United States, Japan, Republic of Korea, UK, Israel. And I think that's it in the top 50. So that's interesting. I'm going to stop my remarks there. I don't, Kastin, you want to comment now or you want to take all the hard questions? I have a question. Whatever. Yep, go ahead. Thank you, Director-General. Maybe just to add a few more observations onto what we have seen in 2010. I think we're all astonished by the staggering growth rate from China, plus 56.2%. Should note that that growth rate is larger than the domestic growth rate that we saw China in 2010. With the domestic growth rate, I mean filings at the Chinese Patent Office. And that suggests that while patent filings in China continue to grow rapidly, that there is also greater internationalization in a sense that more and more Chinese patent applicants would like to see their inventions protected in foreign markets. I think in the case of China, it's also interesting to ask, and we are interested in that, how far can the growth go? One would expect that maybe at some point, saturation would set in. But I think it's important to point out that if one looks at the share of PCT or international application in applications of domestic residents at the local patent office, China's share is still 4.2%, meaning only a relatively small share of the patents that are filed in China make it to international markets. If you compare that to the United States, technologically much more mature market, that share is above 20%. So alone from that, there seems to be still substantial growth potential in the case of China. In the case of Japan, I think there we see a trend that has been continuing or that we could observe for a number of years. And that is that Chinese inventors and firms have really taken up the PCT system when it comes to filing patents abroad. As you know, patent applicants always have two options when they seek patent protection in foreign markets. They can either do so directly through the so-called Paris route, or they can use the Patent Corporation Treaty. And in the case of Japan, we have seen clear embrace of the Patent Corporation Treaty in the last few years. Maybe one note on the United States, the Director General described that the United States, which still is the largest user of the PCT system, was most heavily affected by the crisis. The fall of 1.7% that we saw in 2010 follows a fall of more than 10% in 2009. And if one looks at the data more closely, if one looks at monthly data, one can see that in the case of the United States, applications seem to have reached a floor in early 2010 in January, especially. And since then, they have stabilized. So if one looks at the future, one can probably quite reasonably expect renewed growth also in the US, which, as I said, is the largest user of the PCT system. And finally, a few notes with regard to Europe. I think it's interesting that in the case of Europe, the filing performance seems to reflect the economic performance in a sense that the country that did see renewed growth after the crisis is Germany. And as you all know, Germany was the European country that experienced the fastest economic growth, at least among the major European economies last year. I think maybe the one thing that is somewhat surprising is that we see a 10.3% filings growth from Spain, a country that is going through difficult economic times. But again, here we see that this is part of a longer term trend, firms embracing the PCT system as the main vehicle for obtaining patent protection in international markets. Let me stop here.


Vinath asks, hi, is there any expert out there who can help me personally with a problem in teams that I'm facing for a long time? I'm uploading documents and giving it limited access, but the members aren't able to view it. I tried doing everything to solve this, but the problem still persists. In fact, I'm confused of the options. I'll be grateful if someone extends their help to me and I'm ready to pay a professional fee. Okay, the bottle up for consultation. So there, let me just get this straight, says they're uploading documents, giving it limited access, and the members aren't able to view. Well, the fact that these had limited access, the head just goes straight up on my neck. Yeah, no. It's too limited, is what you're saying. Well, it means that they've gone in to potentially remove everyone's permission if they're doing limited access and they're using teams to do it. Teams is inherently about giving permission to everyone that's inside that group, the security group, for permission. So if they're saying limited permissions, one are they internal or external? It's not saying, because that can change things as well. Because if it's not enabled for external access, then they've created a team, then trying to give some of the, yeah, so there's all sorts of, I have more questions, as we say. Right, this is one of those classic, like wish we could ask some follow up questions here. So what, where are the, what are the users? Are they internal or are they external? Is it what type of channel is it? I mean, what kind of library or do you have the content in? What kind of permissions, then what did you go and modify or potentially break within that? I mean, if you're trying to, because teams, by nature, is meant to be very flat. So I'm a member of a team, if it's a public or private channel, I have access to that. And then you can, you know, control access down to the document level. I mean, are you doing document level permissions? And breaking inherited permissions. Right. Right, yeah. But you, you can do that. You can create a SharePoint library, create very specific permissions to a sub. Like if you want to be able to share the link in or share a library, to put it in a tab within teams, to openly discuss it, but only the people that have permissions can access that. You can do that in a, in a library. And just, you know, only those named resources can have access to it. So it really depends on who they are, where, where they are, and what permissions that you've set. And the big thing to remember, yeah. As I say, the big thing to remember too for SharePoint is a lot of times when you're doing limited access, this used to be somewhat important and with teams it's more important. But if they don't have access to the site at the site container level, there's a lot of, especially there's a lot of new stuff in the modern interface that if you don't have access to the site level, you will not be able to do certain things. So I can give you access to only one document in the entire site. The only way you can access that is if you have the direct link to that document, otherwise you will never be able to get to it. So if you have access to a document, but you don't have access to the site and you're trying to access it through teams, you will not be able to get to that document because the document interfaces through the site interface. And so what's likely happening is he's giving them access to one document and then he's cutting off their access to the site and then they're not able to see it through the team. Or they're looking for it through the team when they should just look at it through the have him resend the link to the document. Yeah, well, and it's also, so a lot of times people do unique, so there's unique permissions and then there's link permission. So there's, you can have access to a document through a link, you can have access to a document through your login. And those are actually two separate things and what will happen is the URL. There's like three separate URL parameters that will happen around permissions. And if you're sharing one link as a tab in Teams, but you've given access to a different link, that link actually won't work even though you think it's the same link.  Otherwise, it may actually be the wrong link that you're sharing anyways. So permissions, like you said, permissions, I agree with you, Sherry.  You can even go higher than that. What's the organization set for the whole tenant to go, can you even do external links and you're trying to do a specific person thinking it's going out if it's an external party and it might all just be completely shut down. I said, I'm sending them a link. I've created a link thinking that they can get to it, but being external and they then can't get in. So how did they have to do authentication to come in? Are they coming in through the right authentication with the right email address? Is someone getting in and the other one's not? There's so many things around links that can get so complex fast. And until you know exact scenarios, we've got a lot we can really talk about on that one. And I just wanna clarify something that you said, Christian, because we're talking at kind of a higher level, but what I find all the time is people don't even realize, A, there's a SharePoint site behind the scenes that stores the documents in Teams. And B, you could have different libraries in that team. So there's one default one that feeds the channels, but there's actually, you can create in that SharePoint site a whole another library that has different permissions. And that might be the answer because by default that main library, everybody has collaborative.  Yeah, that was kind of my point. Like, depending on what he's done to the standard site, which you should never mess with, go create, again, if there's a need for, if there's a sub team within that larger team and you wanna create a whole another site, maybe you don't even wanna create a private channel for those conversations. You just wanna be able to share with three people as part of the larger team, a library with one or more documents that are only for the four of you to discuss, that's fine, knock yourself out and do that. But yeah, it's when you start messing with the other standard locations, that's where it gets me nervous. Don't mess with that general, don't mess with that general stuff, don't mess with that first primary library, let teams own it, that is teams is, we don't need to take it away. Yeah. Yeah, and you see that. And then they do a shared channel or a private channel and then trying to work out and then go, I need the document under the private channel to go out now. And then you start to see a whole another raft of stuff going on, not understanding what happens with the private channel and then it's a whole another SharePoint site with lockdown permissions, because it is a private. Don't talk to each other anymore. Don't talk to each other at all. Yeah, yeah. Yeah, so we start to see all sorts of complexities going on. So I don't understand why this is a problem, I just email that document to those people. I was joking people, I'm just trying to be funny. Don't do that. No. And when they can't find it Christian email it again. So it's at the top of their inbox. And can you now email again the more current version because the one that I have is from so six months ago. Yeah, that's awesome. It's funny because it's true and it hurts. But is it the final one? And I've got another final, it's today's date, but did you have one for tomorrow's date? So we're all in final envy. Final, final, final. Final, final, final.


Hello to everyone. My name is Nidal Gesoum. I am professor of physics and astronomy at the American University of Sharjah here in the United Arab Emirates. I have done astrophysics research in many different parts of the world including having spent a couple of years at the NASA Research Center. I continue to do research here with colleagues from the UAE, from the Gulf, from Europe and from the US. My most exciting activity is when I involve students to have them discover space, discover the cosmos and participate in research that can uncover new things in the world. There are reasons why I think young people should be interested in space science and space technology, space industry. First of all, space has become an integral part of our lives. Now we do not live without satellites, we cannot live without satellites. Whether for telecommunication, all the TV channels that we receive, the navigation, for example GPS, now we can't go anywhere if we don't have GPS, remote sensing. All kinds of activities, even sometimes when there is a problem that needs some intervention, we need the space technology to pinpoint the location of a person or a vehicle or something. So space has become an integral part of our lives. In addition to this, space has shown us that there are an infinite number of avenues where people can do research, can do research and development, can innovate, can integrate things that we have learned from Earth to space and from space to Earth. Everything that we have done here on Earth has been applied to space. And actually a lot of the things that we have been doing here on Earth started from space because we needed to develop, for example, lightweight laptops. We needed to develop water filtering techniques because we need to filter the water and recycle the water when we are in space. We can't keep on bringing water from somewhere. All kinds of health devices, how we monitor our hearts, how we monitor our health, medical aspects. A lot of things that were initially developed for space and for space venues, for space travel, for the space station, for travel to the moon, etc., have now become standard applied devices and techniques here on Earth. Plus, space, I always tell people, offers the fascination of discovering a new world, a new frontier. And youngsters are always fascinating, want to discover something new, want to go somewhere, you know, as Star Trek used to say, where no one has ever been before or discovered new places. And so for all these reasons, I think space offers an exciting and very promising aspect or venue for youngsters to implement their creativity, their interests, their discoveries and every skill that they have learned at school.


of the retirement account is generally the idea. So if everything remains the same, albeit higher tax brackets now than when I take the money out, and therefore I want the deduction at this point in time to defer the taxes. Typically that's the way you wanna do things, defer the taxes. But what if you think that the government is overspending and they're gonna just bankrupt the government and at some point they're just gonna have to tax, really tax everyone? Well, then you might think, or if you don't have much money right now in earnings, then you might think, hey, I just rather pay the taxes now and then when I take the money out, that's when I don't pay the taxes. And in that case, you'd have a Roth IRA, in which case the growth of the money might be a tax-free situation, but it's not gonna be taxable when you take the money out. So that means that you're not getting a tax benefit when you put the money into a Roth IRA because that's the point of a Roth IRA, it's inverted. Number two, if you're filing a joint return and you or your spouse made contributions to both a traditional IRA and a Roth IRA for 2023, don't use the IRA deduction worksheet and these instructions, instead see publication 598 to figure the amount. So obviously it's a little bit more complex, different worksheet to use. Tax software is of course greatly helpful for these types of calculations. Number three, you can't deduct elective deferrals to a 401K plan, 403B plan, section 457 plan, simple plan or the federal thrift savings plan. These amounts aren't included as income in box one. So in other words, you might say, well, isn't the IRA the same thing as like a 401K plan or a 403B plan or a simple or something like that? And the general idea is like, well, yeah, it's the same idea, but if you had W2 income and a 401K plan, it would be reflected by the employer in the W2. They would have already lowered box one and therefore your taxable income would be lowered when you just input the W2. So it's already basically taken care of. You can see that because you'll see it in box 12, I believe, and box one will typically be different than box three and box five because it will possibly be a reduction for federal income taxes, but possibly not for Medicare and Social Security in terms of income. Number four, so if you made contributions to your IRA in 2023 that you deducted for 2022, don't include them in the worksheet. Number five, if you received income from a non-qualified deferred compensation plan or a non-governmental section 457 plan that is included in box one of your form W2 or in box one, a form 1099 NEC, don't include that income online eight of the worksheet. Similar scenario we talked about before. The income should be shown in A, box 11 of your W2, B, box 12 of your form W2 with code Z or C, box 15 of form 1099 miscellaneous. So similar type of scenario, it should be reflected in those cases on the W2 form and therefore you shouldn't get a deduction because it will already be reduced in line one of your 1040 box one of W2. So if it isn't contact your employer, okay, six. So you must file a joint return to deduct contributions to your spouse's IRA into the total IRA deduction for you and your spouse online 20. So note that if you're married, you have to file joint or separate. If you file separate, the IRS is gonna be skeptical on many kinds of deductions because it's likely that you might be trying to manipulate if they weren't, then people would manipulate the system between joint and separate in ways that would not be good, right? So seven