All right, everything we've been doing so far, we're going to go back and go over again a little bit in a slightly different way. So far, we've been looking at particle dynamics, and in fact, if you remember, this is very much the same sequence we went through in Physics 1. We did the kinematics first. Remember what that was, the kinematics? Fill, kinematics. Remember that? Well, how do we start? How do we start class? What do we look at? Both here and in Physics 1. Well, yes, specifically linear, I guess we started, in fact, we started with 1D, but what we were looking at then back in kinematics is nothing more than position, velocity, and acceleration, and the interchange between these two, or these three, and of course the fact that all of this happens over some time period. We started with linear, then went to curvilinear, did a little bit with 3D just to touch on it some. But that's all we looked at the first couple weeks in here, and spent even more than that in Physics 1 doing just that. Then we went to the kinetics, which is where we bring in the business of how do we make sure we know what the accelerations are and how those other things are affected. And we had three different ways that we approached kinetics problems. Our first was Newton's law, which worked very well for general type problems, especially if forces were constant, because an acceleration's constant is a pretty straightforward problem. But it also worked well for any problem that directly involved acceleration and or forces. Then we looked at the work energy method for solving kinetics problems that worked real well for position dependent problems, especially those that had changes in height in the gravitational field, which was a change in the gravitational potential energy. But also, problems where the position of the object in the problem affected how much of a spring might be stretched in those problems that worked real well for the energy method. Then we just had a little bit with the impulse momentum method and how that affected our ability to solve certain types of problems worked very well for time dependent problems. Now we're going to kind of quickly go over almost all of kinetics in a different way in that now we're going to do rigid body dynamics. So some of this will be as a lot of what we've done has been a bit of a review from Physics 1. However, if you remember in Physics 1, when we looked at rigid bodies, we only looked at them as objects that could rotate and that was all. What we're going to do in this class, we're going to quickly review pure rotation. But then we're going to put the two together and get a more general motion solution to these types of problems where we have objects that will move to different places. But we're going to take account of the fact that the object is a real size object and its particular orientation can very much affect the problem and its solution there. But then we're going to go over these things again with strict rigid body dynamics put together in general motion where we look at objects that can translate and rotate which the simplest example is of your car tires. They rotate as they move, but they also move from one place to another. So we'll do exactly that in a little bit. So to open with let's define what we mean by a rigid body. Because if we don't have a good definition of that, it's not going to be clear just what we're talking about. Especially when we get to certain problems in a little bit where we're going to have not one, but two, three, maybe even four rigid bodies in the problem. And we have to understand why they're rigid bodies, but the union of them is not particularly a rigid body. So imagine we've got some object here. A rigid body is that such that if we place on it three arbitrary non-colonial points they of course will make up a triangle. Whenever you have a triangle you have lengths of certain sides, little letters for that I guess. You'll have angles, alpha because it's near A, we'll call this one beta and I guess we'll call that gamma alpha beta gamma. I don't know what the Greek letter for C is if there was one. I think gamma was G, but there was no C. It doesn't matter as long as we've got some labeling system. So a rigid body is that such that these things are always invariant. Length of the sides, I guess I'd have to put a symbol for line segment. The line segments A, B, and C are constant as well as are the included angles, alpha, beta, and gamma are also constant. The values measured at any time during the problem for those three things will always be the same. In other words, what we're learning in strength materials about strength does not apply. Oh yeah, this is not an elastic solid like we're looking at in strength materials where that whole class depends upon the fact that real objects deform. So this is very, very much different than that. But don't forget in strength materials we don't have acceleration of any of those things. We're always under static equilibrium. In this class we're rarely under any situation of static equilibrium. We'll have some situations where the acceleration might be zero but only in a particular direction or in a particular way but there's always at least something accelerating in this class nothing accelerates other than our ability to absorb no material. Nothing accelerates in strength materials which is why it follows directly on the statics. So what isn't necessarily constant, those things are always constant. What may or may not be constant and depends upon just what the problem is, the location of each of those points might not be constant. If we had a, one of those points was the point about which an object rotates then, for example if it was point A, then position vector point A would be constant but as the piece rotates none of the others are constant. That's where we're going to get the object movement and then of course follow from that is that the velocities of each of those pieces may or may not be constant. And then of course the accelerations not only may or may not be constant may or may not be zero. Any one of those might be constant but any one of them might not be either in this class. However, what is inviolate is the shape of the object itself but what can change with the second part is that the object's orientation at any time can change. Remember those points A, B and C are arbitrarily placed and that's sufficient to define them in the entire object. So that's our strict definition of rigid body. We're not going to really bother looking at it in any detail because most of the things we're going to look at are just so obvious and rigid bodies that we'll be fine with it. But we will be looking at different objects linked together as we look at linkages and different machines and how they move, the dynamics of those type of things and we'll be concerned with then the interaction of several rigid bodies. So of course a rigid body can move in translation. What that means strictly to us is that given any two points on the object we don't need to define three that's sufficient for the shape for defining translation we only need two and there could be any two objects any two points on that body it's in translation if the kinematics of those two points are equal to each other. So if A moves from one place to another then that's the same movement that B undergoes for any two points on the object which is sufficient to define translation from the entire object. And if that's always true then of course it follows that the velocity of A and B are always the same acceleration for A and B are the same and we don't need to go over that because that's no different than the particle motion we just looked at. If all points move exactly the same then let's not look at them all, let's look at only one and that's exactly what we did back here as particle kinematics so we don't need to go over that again in any way. What is going to be a little bit different as we get a little bit farther in this is there are some motions that don't appear to be translational type motions. Don't forget that the path from one point to the other from A earlier to A later could be a curvilinear path as well. One good example of that is a type of example if we have a sign that can swing on two cables or two linkages of some kind even though the points don't undergo straight line paths as they go from one place to another they'll go kind of a circular path each point undergoes exactly the same path so the entire sign is in translation even though the cartoon picture doesn't quite look like it that is a true translational motion problem in fact a curvilinear one and we don't need to look at all the different points we would have been sufficient to just look at one particular point and know exactly what all of the sign is doing so a lot of students think that that's a rotational problem rather than a translational problem but it's not so then that brings us directly to the rotational motion that we're going to look at and we'll look at pure rotation today just to warm things up a little bit and then we'll put the two together translation and rotational motion together as we look at a more general type approach to these problems so rotational motion most easily described with a simple circular object rotating about a single axis of some kind our reference points then are some line on that object will move through some angle so our position is governed by the angle that makes for some reference line just like our position vectors make some position with respect to some reference point and then of course we're concerned with the changes in those angles as this object undergoes some kind of rotation these are vectors because there's a different direction things can move in rotation and in others we have to take that into account we will use the right hand rule for that vector notation which is common throughout all of science and engineering as far as I know there's rumors that in Russia they use the left hand rule but with the interaction of the sciences between the Eastern and the Western I'm sure that we all agree by now but remember that the deal with that is put your fingers, curl your fingers in the direction of rotation that automatically orients your thumb in a particular direction in this case it would be up and then that will be the direction of that vector that represents rotation so we'll be able to represent it in several different at least two different ways where either the direction of a regular vector or with a little circular arrow type notation either way is sufficient but we will be getting to several cross products and cross products are much easier to figure out with a straight line vector than they are to figure out with a little curly representation of the very same type of motion once we establish a position of an object and it's changing position then of course we're interested in its velocity the angular velocity is defined as well exactly what it was in physics one and the first part of this equation which is this semester which is the change in position with respect to time time rate of change position we look at it in both average terms and instantaneous terms and this is no different than what we did with our translational motion as we looked at these things and we can also use that dot notation so this should all look very very familiar there's no difference between the concepts and the notation with this rotational motion that we used in translational motion the first part of the term other than the fact we're looking at a different type of motion so we use a different symbolism for that but the concepts the general notation the general mathematical notation is exactly the same and then of course we want to pay attention to how the velocity changes and then that brings us to acceleration which again is laid out in exactly the same way it was in translation as an object changes its velocity we can look at the average change and we use an alpha to represent that make sure that your alphas and your a's that we use in translational acceleration don't look too much the same put a little artistic flair on these symbols so that you make sure you know and you make sure I know what it is you've written so the instantaneous acceleration was the average acceleration as measured in this and the time and that's exactly as before being on the first derivative of the velocity most of what we did in physics one if not all of it and a lot of what we did earlier was constant acceleration a lot of that will be the same here but we'll look at some non-constant acceleration problems just because you guys are that much brighter and then remember that the double dot notation applies in cases where the acceleration is constant as before then the average acceleration and the instantaneous acceleration are equal to each other because they're never changing that's kind of our definition of average all right, if you remember too as we go through everything else all our kinematic symbols between translational motion and rotational motion are perfectly analogous to each other and you can get from all the translational equations to the rotational equations by simply swapping out the variables one for one position for position velocity and acceleration and you get exactly the same things all right, so we'll do a couple we'll do a little bit here today with pure rotation and then on Monday we'll step into rotation and translation together or what we just call general motion so let's look at the type of problem we're going to see in this class imagine some kind of link arm that rotates around a particular point it may or may not be joined to some other object and we need to see how that moves this is exactly the type of things you see in robotics but we're for now just going to look at a single arm you can imagine that that part itself is indeed a rigid body but the object as a whole depending upon what the other arm does how it moves what happens at the other end of the object the two together is not a rigid body because we could certainly imagine a triangle made out of the ends of each of those and that triangle is going to change shape radically as we go through the problems so imagine we have an arm here whose angular velocity is changing uniformly such that it goes from 10 radians per second to 25 in 10 seconds and if you remember from physics one all of the angles when used in calculations must be in radians rather than in degrees we might talk about them in terms of degrees I don't know about you I'm a lot more comfortable talking about angles as measured in degrees and radians when I'm just thinking off the cuff but for the calculational purposes we need to keep it in radians so given that change in velocity this arm is one foot long want to find out something about this point here we'll call it point P want to find the velocity of point P actually that's the speed and also find the acceleration of point P we can do that in vector terms actually we can do velocity of point P as well in vector terms I'll see what you think we should do with that so if you can remember because those are actually translational quantities that come from the rotation of the object then also find the change in angle all of the distance traveled by the point P as well so want to find those three quantities this is mostly just review from what we've done before think about this velocity though remember it's directly a function of the angular velocity of the piece and the distance from the center of rotation so if you remember it looks something like that and that's going to be different at different times because the velocity is changing remember what is this in terms of a vector quantity how do we give direction to that I think you said it no? unit vectors we need some coordinate system that's going to work for this and I don't know if there's a better one than the normal tangential coordinate system we established some time ago the unit vector and the tangential direction depending upon which direction the object is actually moving and the normal component perpendicular to that and always directed towards the center of rotation and that's all that point is doing it's in curvilinear motion about some center point defined by a rigid body pure rotation about the same point so we can call that then in the normal direction tangential direction it turns out and this is not something we used in physics one but I expect you to be able to handle this here this can also be determined by the product of omega cross r that locates the p the point p from the center and let's double check that let's see for this picture our fingers in the direction of rotation that puts my thumb into the board so omega is directly into the board the position vector I orient my right hand such that I go from omega into the board towards r going out to point p that orientates my hand in this way and that's exactly the velocity I would expect the point p for that rotation the direction of velocity for that rotation so this is not something we could have done without a good clear idea of what that omega vector actually represents this cannot be crossed with rp itself we need the right hand representation of that kind of motion itself with changing omega from 10 to 25 seconds we can't really work that number out we could pick it at a particular time we're not going to bother with that however when we do the acceleration we'll also need a particular time so we might as well pick one and so let's say at 5 seconds what is then the velocity of that point and then also use that same time to find the acceleration of those points too hopefully it's obvious that at 5 seconds we're going to be midway in between here because I did say the change in speed was uniform so halfway between there is what just 17 and a half so our velocity then would be rp is a distance of 1 foot the speed at 5 seconds is 17.5 radians per second and the direction is in the tangential direction which we don't necessarily know the specifics of the point because we don't know the angle on the arm itself but that's sufficient to say the tangential direction since the velocity was changing we needed to pick a particular time so what the heck, it equals 5 seconds what about the acceleration of point p that arm speeding up which means point p is going to speed up as well we need to figure out by how much and again let's just pick it and solve it at 5 seconds so what's the acceleration of point p, how are we going to find that and then let's just go through the mechanics of it with the numbers well since the arm is spinning faster and faster with this changing angular velocity then it's linear velocity is going to be changing and since the angular velocity is increasing the linear velocity is going to increase too that'll be in the tangential direction so we'll have the tangential component as nothing more than the time rate of change of that tangential velocity well that v dot t is just the acceleration so we can figure out how the speed of the point itself is changing is that sufficient or do we need something else to go with it we're going to have a centripetal component for this as well that's exactly what we looked at in physics one we only looked at uniform circular motion but no I guess we did a little bit of accelerated circular motion but not much so we need to take into account that was the very same thing we did when we looked at the normal tangential particle motion anyway we're looking essentially at the motion of a single particle at point p so those things we can all find out there are slightly different ways to take care of that though too that are a little more sophisticated than we've had before the acceleration of point t sorry the tangential acceleration of point p all of these are point p is the distance point p is from the center times the angular acceleration we did that in physics one as well and then this will be in the tangential direction this is also a cross product in the same way that the velocity we're going to have that a little bit greater level of sophistication that we didn't have in physics one as we look at all these different points so let's see what that means it's spinning faster in the clockwise direction it was going 10 radians per second I said in that direction it was going 25 so the direction the speed is increasing is in the same direction as omega is that puts the acceleration vector also directly into the board rps was as it is before so the direction of this cross product is the same as the direction of this cross product because omega and alpha both have the same direction into the board in this case and that's what we'd expect if alpha is in the board cross it with r that gives us an acceleration in the tangential direction in the same direction as the velocity at that instant so that also makes sense and that number we can figure out because we've got enough information to figure out the acceleration, angular acceleration is there and we know that the distance is one foot from the center the normal component we can figure out in a couple of different ways we can do the v squared over rho I don't remember if our book uses rho or r my recollection is they use rho but r is sufficient same thing but this is also oops sorry I need a vector sign over that one vector sign over this one as well so this is in the normal direction another way to find that out is if we make this swap r omega equals v we can put that in here we get r squared omega in a normal direction this is also however a cross product and it's a little bit more involved one it's actually two cross products it's omega cross omega cross r where don't forget when writing cross products the order of the two vectors is crucial if you swap the order of these then you've got the negative of that so you have to do it in the right order so we need those parentheses in there what's the term in that case it's not commutative or it's an associative whichever we need the order in which we do these cross products so this one's harder to imagine because it's two cross products however this omega cross r the one we have in that second parentheses we've already got and that's the tangential velocity so I'll keep it a little more in general rather than say point p it's tangential to rock velocity at any time and so that one we can do let's see remember omega's into the board the tangential velocity is slightly down as I've drawn it so when I cross those omega into the board crossed into t gives me my thumb directed right down towards the center which is exactly what we know of the normal component of the acceleration should indeed do so by whatever means you wish to do that you're free to I think the easiest thing to do is well we've already got v the velocity of the point calculated we know what the radius of the rotation is the distance that point p is so I think it's just as easy to use that form right there with all the pieces and not do the cross products we'll do the cross products at times it's just probably not the most efficient way to do it here since we don't have any specific angle on that arm at any one time we just know how it's changing so take a couple seconds figure out what this velocity is sorry that acceleration is and leave it in normal and tangential components and we'll be fine and then we'll come back when you've got that to figure out the distance that point s actually travels now is that supposed to be r omega squared or is it r squared omega r r omega squared right thanks for staying away calm yeah r omega squared yeah the units wouldn't have worked out and that's probably what you were looking at notice that the same components that are here are also the scalar parts of the cross products because these by definition by definition these vectors are all perpendicular anyway so we've already got v at 5 seconds remember do this all at 5 seconds because it is changing changing value the main part you need is alpha got it already ok that we already have so that one's easy and then you need to figure out what the acceleration of the point p is but that's the most easily done from r the rotational acceleration and we have enough information right here to figure out what the rotational acceleration is remember I told you that it was changing speed uniformly which is the same thing same constant acceleration got the parts filled already not hard 5 seconds 10 seconds I had to pick some number since I'm the boss I had to pick which number so I picked 5 seconds that number that's just enough to tell you what the acceleration is the angular acceleration and then we had to pick some point because all of these values depend upon what's happening at a particular instant since it's constantly changing so it's just an arbitrary arbitrary choice you should be used to the fact now that adults are always arbitrary in the decisions they make certainly your parents are minor sorry about my own dad alright David let's see v squared over rho is the easiest way to do this so you should be getting a magnitude for the normal acceleration of point p as 17.5 radians per second quantity squared over the radius or the distance from the center of rotation which is the one foot and notice we get units then of what seconds what seconds no we don't yeah we get it yeah no wait we don't like those yeah no no this isn't radians this is feet that's where the trouble was units will always tell us what we're screwing up now we get feet per second squared because that was 17.5 this is just the one foot I messed that part up so now we're okay we caught it that's 306 feet per second squared 306 feet per second squared for that part and then the tangential magnitude and then we're just going to multiply by the unit vectors so this is all we need is just the magnitude's normal part I need just r alpha and alpha is the change in velocity by the time it took to make that change 5 minus 10 radians per second over the 10 seconds it took to do that so that gives us again feet per sorry feet per second squared and that's 1.5 feet per second squared and so we've got now the entire acceleration let's put it back together 1.5 in the tangential direction plus 306 in the normal direction so that's far and away the greater part of it per second squared so now we know the acceleration of point P what's going to be very important to us in a little while is we're going to need the acceleration of point P so we can figure out what the acceleration or end of the other arm is that's exactly the type of thing that's done in robotics you need to know the acceleration of all the points assuming that all of them are rigid bodies linked together so the last little bit I asked you to find was the change in or the distance traveled by point P in 5 seconds we know the time we know the acceleration we know the initial velocity sounds to me like a constant acceleration of waging 1.5 A T squared plus B I T then we've got all those numbers there comes out to be 175 feet the change in angle that went with that it's not what I asked for now and then done rp times delta theta the change in the angle is 175 but you could have done that in physics 1 which brings us to the next part of how all these things interrelate to each other and a lot of it comes out to be just what we've had before any one of these or alpha d omega dT then it's also true that's the differential form it's also true that the integral form applies as well if we don't have constant acceleration if we have acceleration that changes with time then we're going to have exactly that piece there to it and the same thing the velocity part using our definition of velocity and differential form we're going to make it into integral form and it's those times when either of these or both are constants that they just come out of the integral and that's most of what we did in physics 1 but not necessarily a luxury we'll enjoy it here because you're a more sophisticated student if you remember we did have one little piece that I warned you was a part of this that was often forgotten so I'll give you the same warning now if we solve this one for dT we get dT equal to d omega over alpha if we solve the second one in the same way we get dT is d theta over omega since those are both equal to dT if we combine those two then we get alpha d theta equals omega d omega if you remember I gave you A dS equals B dV when we were talking about translation and that's one of the pieces useful for solving some of these problems that students often forget especially when acceleration is a function of time and then you can integrate this in effect it integrates to the kinetic energy but don't forget those again as a piece of the solutions that we need to as we go through these real briefly just so you remember for constant acceleration problems which several of ours will be especially when we get to the point of general motion and we're going to be combining rotational acceleration and letting one or both of them be constant to allow us to get our feet wet and those type of problems that we have looked at before so it's still very useful to know what the constant acceleration equations are and they're exactly the same form as were the constant accelerations in translational motion for example the bulk change in position angular position with time but that's also equal to the straight arithmetic average of the two numbers this is also one of the constant accelerations equations that students tend to forget just because it's so simple to calculate the average students sometimes forget a very nice thing to do we also have as one of our equations alpha equals d dt r omega 2 minus omega 1 over delta dt remember the deal with these constant acceleration equations is that each of them has four components in them if you have those same four components that's the equation you use to solve this one has omega 1 omega 2 time and change in position this one has acceleration the two velocities and time and the only reason I'm giving them to you in this order is the order I gave them to you in physics 1 below those many years ago the change in position is delta s equals v i delta t plus 1 half at squared only this time we're using our angular kinematics symbols rather than our translation and then the last one which almost no student forgets is v2 equals v1 plus 2a delta s only we cast it in angular terms rather than in terms of translation exactly the same in translational form units all work out just right keep an eye on them we will have the additional parts though that I've already given you of the translational velocity of a point is the cross product of a vector is defining its motion and the tangential acceleration of some point is also a cross product and the normal is yet a third but it comes in two flavors just in case you're not in the mode to do three cross products because this one you've got to do this first cross product results in a vector then you've got to do the second cross product with your result and you can't mess up a single minus sign you can't mess up a single multiplication you've got to get it all right alright so let's look at a non-constant angular acceleration problem imagine a small motor here used to run a much larger blower of some kind by means of a belt going around the two actually this is a constant acceleration problem we'll do this and then we'll do a non-constant acceleration problem alright so the motor has an angular acceleration of two radians per second squared the radius of this let's call this one a and this one b the radius of the motor 0.15 meters and the radius of the blower pulley is 0.4 meters so this is a constant acceleration problem one still but it's getting a little more complicated now we have two rigid bodies connected plus it's going to bring up one that briefly addressed in physics one but we didn't need to put a lot of weight into it other than the fact that we considered it true so I want to figure out the acceleration and velocity of 0.p after two revolutions of the motor pulley a so instead of defining that by time a point in time we can find it by a particular position so this is a constant acceleration one it's not going to take anything more than the type of stuff we had in physics one and then this time it can be a little more specific with the vector since we're taking that point at the bottom there the acceleration of 0.p a normal component and a tangential component and we know something about how to figure out both the loads and then the velocity of 0.p is going to depend upon whatever its velocity is at that time but we're going to need that for the normal component anyway for the v squared over r that's probably the easiest way to do it with the vectors if you want across products give that a simple coordinate system okay so with a couple minutes allotted to you see if you can't chug through through that rather quickly notice that there's a a ratio between the angular velocity of a and that of b and the angular acceleration of a and that of b so the velocity and angular performance you need in the equations are those of the blower pulley b rather than the motor pulley a at that phase speaking German do you speak German yeah so it can't be that I don't either so it would sound terrible so what we're given here with this is 2 revolution that 2 revolution is you're sort of given delta theta not specifically because remember revolutions is not a measure of angle we need radians invert that 2 revolutions 2 pi radians per revolution and then you have it gradients remember all of our angular measures as used in the equations our radians these are sometimes referred to as as engineering they're very common to be speaking in terms of revolutions per minute etc that's got to be a picture of that like our little ten and I don't know if it gets all the way up to the board one important assumption we need to take here and it's going to be very important throughout the next the rest of the class is we're assuming through all of this and it's not always true and you can confirm that with things you do with your car we're assuming that the belt does not slip that there's a no slip condition between the belt and the fluids if it does slip things are all together different so we have to assume for this that the belt does not slip that's not necessarily the case when you're starting up a motor which we argued because we have an acceleration on the motor and that's the squealing you'll sometimes hear in your car if your fan belts and other clay belts are slipping especially when you turn your power steering you turn your wheels bomb has that happened to you recently? the wheels are pretty far to the side it really puts a lot of strain on the power steering motor and you'll hear the belt slipping don't try to pick up a girl in your car with squealing belts that's what I always say is that not working? certainly we can multiply 2 times 2 pi together this is delta theta so what this really is is delta s since you have the distance in there what's that one? once you've got delta theta then you can find the distance that point traveled by doing r delta theta you can come up with the velocity of point p based upon the velocity of any one of the points on the motor pulley because they're intimately connected by a non-slipping pulley that's the purpose of using a chain instead of a belt insurers non-slipping because of the teeth on the gears and the rollers on the chain so it's many of the same type of things we had to figure out before the velocity of this point p which you can figure out the velocity of any point on the motor pulley since they're going to do the same with the belt non-slipping but then you'll also need the acceleration of point p and that you've got to get using the ratio of the diameters for any the acceleration of the motor pulley I put in the work order to get that fixed but I just couldn't get over this morning I really found it this morning because we get reflection we have the sort of shiny window sills over there and they cause enough reflection on the board that it's a distraction for the camera to believe me we're not amateurs we do have a professional in the room does that make sense Phil, alright you could do it with these cross products I don't know that it makes much sense to do that it will for some complicated problems where we've got lots of different positions on these things but we need a couple pieces as usual we need the velocity of point p of course in the tangential direction obviously it's going to be in that direction and that will be the same as the velocity of any of the other points because they're all connected in the built movement so we can figure that out r omega a remember though that's after two revolutions so we're going to have to find that part and that also because rb omega b but r omega a and omega b are related by the ratio of their radii pretty quick fix so the angular velocity of a since it's constant velocity we can find that out after two revolutions from one of our constant acceleration equations we're given the acceleration and the change in position and assuming it's starting up from rest you didn't ask I said when starting up it won't slip but that was the discussion about belt slippage I was making sure that you listened to me at all times rather than just occasionally stopping by and listening once you find the angular speed pulley a after the two revolutions then you can find the angular speed of b and the velocity of point p and then once you've got the velocity of point p then you can start figuring out the acceleration components the tangential acceleration of point p remember the angular acceleration of b times the radius of b and the angular acceleration of b is again related by the ratio of the radii and those are pretty straightforward to come up with and then the normal component is the velocity of point p squared over the radius of b now lots of different things gears, pulleys, link arms and all kinds of things in mesh so there's going to be lots of radius in these problems, lots of radii be careful pay attention to the fact that you've got to have the right ones in the right place that should give you all the pieces and then you can even figure out the magnitude of the acceleration of point b we're getting there at the end so I guess we've got to make this a get out of class question I'll update the solution it could have gotten out early Chris you got some stuff we'll check it and see if your weekend is starting if you have your doubts alright acceleration of point p is that the total acceleration I'm not quite what I got what'd you get for the components where it goes you know I didn't get the point 6 at point 3 at 2.81 not 2.26 check that you're using the right radii for those pieces what's the difference in p for the velocity of point p for the velocity of point p 1.06 1.06 meters per second w a2 2.7 could be w a I have 2.66 let's make sure we're looking at the right number this one that's after 2 revolutions okay 7 I had 7.09 how do you square them no that's un-squared I had 7.09 make sure we're looking at the same things we'll make it a yeah 7.09 yeah but in engineering we need real numbers we don't work with pies in math class it is not in engineering class it is frying your brain let's see other pieces to look at delta s I didn't figure out directly in the s form well we're getting right near the end let's put these together and then you don't have to stay the whole weekend with me so this should give an omega a 7.09 radians per second that's the speed of a after 2 revolutions at that acceleration at constant acceleration so then you can use that then to find the angular velocity of b at the same time and since a is little it's going to run a lot faster than is b by the ratio of their radii and I had 266 on that one did you get that too Tom ok and then that one we can use it might be the easiest way then for finding the velocity sorry the acceleration of point b because then that would be rb omega b square and we have those two numbers that should be 2.81 mu per second square anyway we have that number there let me make sure that's the normal yeah normal velocity and then for the other one the acceleration um the acceleration of uh the acceleration of point p is the same as the acceleration of any point on the belt so we could have looked at it on the upper piece then 2 we can get that with ra alpha a equal rb alpha b we know alpha a we know the two radii we can find alpha b in fact we just need rb alpha b we don't need to take that apart we can just use it like that so that should have been 0.3 let me show them right now the right one that's the tangential 0.3 which is exactly what this piece is rl and then you can put those two magnitudes together plus 2.81 and you should get 2.83 actually that's meter square seconds to the fourth those are squared and then we square root them notice that once again the centripetal component is the dominating part of the acceleration does that end up what it's okay whether that's the normal acceleration right here but just below it you can either calculate it using b squared over r or you can calculate it using r omega squared whichever you have easier we haven't have omega so it was just easier to do that since the acceleration of any point on that belt is the same as anywhere else since the belt's not slipping then you can set these as even that's also sort of a subtly that students tend to just forget the confusion of looking at new problems right here right there that's the acceleration of point p in the tangential direction of the acceleration of the motor yeah tom you get those and I'm at 2.85 okay yeah that's probably just right alright the 1.065 that's the velocity 1.065 you're trying to get omega from that but that's not what the velocity is oh yes I just didn't have to write it down this velocity okay it's just that angular velocity is the radius there


अन्त्यागिलाई और या भिश्था। बस्था का ज़ी अब यहां देखारखेगया। आप आप यहां ईधला की लिए रद श्लाँग, जूद वो आप देखाग्या थानागा। अप ध़ती होगा जो बआप लिए बियान ती के विन्चान, उगनामीग गरोठ होँ रहा है, लोगने के लिवेंग स्वल्च्तन्ट मेरदा होँ रहा हैं के यसके दिटैमःन्थ कै आंजयां? अवर दाईंै एईज्ँ एकऊनमीच्त कब रहा होनके ठाई था और उसंगे थेटिटैम्नेच्त के आँ अई अख्चीं ठीहां ?? तर्डिन 來 अपने यव दिक सुआए नवात होगा 니, थो और सरःव, because in China there is large growth rate and there are little less growth rates. तो इसकी रीजन्स क्या है, ग़ोद खुरीज इसको कैसे इसको अनलाइज करते हैं, और क्या इसका जबाब देते हैं। तो आज हम सेकंट कुश्टन पर बात करेंगे, कि इंकम कुन्ट्रीज जो दिफ्रन्सेज हैं, अंके बारी में गरुच छिए हमें क्या इनस्चाएट देते। पहला कुस्टन तो आज है क्या गूड़ ग्रुच छिएं क्सक्ट्रीज अद्बाब और सेक्टेझ? कि जो इस वक्ट अत अजँस्टन इंक्ट्ट्ट्रिज हैं, रीज आन पौर की दर्म्यां, उसके बारे में गोल सुरीस हमें क्या बताताती है?  यज़ेई उस की रेजन प्रवाईट करतें, ग्रोट थ्योरीज चागदिस लिए आप प्रप्टिएश। अर फुँचर के बारे में के वर दू दीस, फुट्रीस प्रेदिक्त अब दा फुट्र दिस्टिबूशन अप दवेल्त अपनेशन, या आई तो दिफ्रन्स दिस हैं रिच्ट पूर में. इंबिरिकल के आवीटेंस या इस फावले से उसको स्टेटि करनें कि लिए बवसारी स्टेटिस हुएं, इक सिंपल सी इक रिग रेग़्ेशन इखुशवन यहम से हम उसको युज की आगे और हम असको समझ लेदें के वो किसरा से इस बाक को स्टब शटीख करतें. आप याद़ा को यह सब रब लाग आप वाए याद़ा कि आप ती ती बआप थी आप अप ख़ DANIEL, आप पेरी धािनग्ये लेए अब ती आप पषक रब एद़ा कि यह आप बदादादीट ड़ादा आप देटा आप. पर कपिता इंक्यम है. आई कुन्त्री को लिय क्या अगड्टने के हम ने... क्रोण्तेजेँका different कुन्त्रीस का ड़ेता है. और ती वन और सेखन में है ती वो थी सेग्गा थो ताए्म पीडित कि लेए बेएं. 0 तायं पीडितोर वान तायं पीडित. जीरो ताम पीरीडग रेद ने कि सेझा कोई लोग या सेझा ती भान की होंग. इस इं दोनों का सेजा थे आप को कंट्री आई का इस पीरीडग के रर्ञ में ग्रोत रेध वताएग. left hand side पर क्या, dependent variable क्या अपका, growth rate क्या, between कुन्से दो time periods आपका, T0 and T1. And on the right hand side पर इसको न किस को, इस ग़ोट रेट को किस पर regress कर रें, alpha, constant. And we regress यस को न पर regress कर रें, country, i का जो zero time period में income level आपका, on that, regress कर रें. Plus heirate. So this is a simple regression in the course of your econometrics. You study these things here. Now what does this mean? If the value of beta is important, we take it as, if beta is zero, we take it as a simple case. If beta is zero, what does it mean? On the left side क्या बता है, growth rate क्या? During that time period, we have taken two time periods, zero and one, there is growth rate between them. So if beta is zero, then whose growth rate will be equal to alpha? Alpha is the constant. So what does it mean? That any country has a lot of initial income levels. They are growing at a constant rate. That means poor countries are also growing at the rate at which rich countries are growing. So what is the implication of this? That the difference between rich and poor is constant. If beta is negative, what is the implication of this? Negative means that those countries whose initial income level was high, their growth rate is low, and vice versa. So what will be the implication of this? This will indicate the convergence. That the rich countries are growing at a relatively slow rate because beta is negative. By increasing the initial income, the growth rate will reduce due to the negative beta. And initially, in the initial period, if their income was low, then their growth rate will be high. So beta will support negative convergence. Similarly, if beta is positive, what will be the implication of this? That those countries whose income was high in the beginning are growing at a higher rate and their income was growing at a higher rate, then divergence will increase the differences between them. And in another case, if beta is negative, then it supports convergence. And if its value is minus 1, then this indicates perfect convergence. If this is minus 1, then this means that whatever is the initial level, finally what will happen to you is that ultimately all countries will reach the same point. So this was the discussion of beta's negative, positive and values. So what are the empirical results? In 1986, 16 industrialized countries used the available data. And what are the two time periods? The initial time period was 1870 and the second time period was 1979. So during this period, the growth rate came to the left-hand side. And these are the regression results. What is important in the results? The value of beta 1 is negative. Negative means that it is showing convergence. Number 2, it is almost 1 minus 1.995. So this is the perfect convergence. And if you recall the econometrics, then its standard error is 0.094. It is very small. This means that we measure the beta very precisely. And the value of R-Scare is also 0.87 indicating the health of our results. And how much percent is being explained. So with the help of this sample, these results are supporting this convergence. So this is what I have explained. Now let us look at the graph. In the graph, we took the growth rate of 16 countries on the vertical axis. Log per capita income growth. And on the horizontal axis, the initial income of 1870 is negative. Negatively sloped. The graph we have is that in 1870 per capita income, their growth rate is high. And as a result of this, their growth rate was more. But this sample was a bi-sample. 16 countries selected were industrialized countries. When this sample was increased to other countries, then this graph was made. Now the negative relationship in this was so strong that it was not strong. And the value of beta was almost minus 1. That was almost half. That means that our sample was a bi-sample. In this graph, we took a picture of the perfect convergence. And further, when many other countries participated in this sample, when the sample was increased, then the convergence was almost over. In this diagram, you can see that there is no negative relationship between the initial income and the growth rates. So, from this point onwards, the convergence that we talked about, was an absolute convergence. If without any condition, all countries will converge and the low income will grow at a high rate and the high income will grow at a low rate and they will converge. But from this point onwards, the convergence is not absolute. This is conditional convergence. Conditional convergence means that if some conditions of those countries will be the same, social infrastructure, human capital, rule of law, what is the condition of the institutions in that country, what is the condition of the rule of law, what is the condition of property rights, these are the things. Degree of openness to foreign trade and some macroeconomic variables. If these things are similar, then their steady-state level will be similar. If these things are different, then their steady-state level will be different. Every country will come at their steady-state level, but due to the different level of the steady-state level, they will not converge. So, what is the implication of this? If the government tries to improve its institutions, improve the rule of law, improve the saving rate and improve the human capital, which we have read, focus on research and development, then in the end, there is a chance that they can attain the higher income growth rate. Institutional changes are very important. The steady-state income level will be determined. Favorable social infrastructure, it can potentially lead to the higher steady-state income level. In institutional changes, economists talk about discouraging current-seeking activities and encouraging productive activities so that the country can grow in that way. Thank you very much.


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That's what happens when you look away from the page when you're doing mathematics. Actually, your question, by the way, lonely piggy, if I have any advice, when you're doing a problem, don't look away too much. Because when you look away, you might forget to put down a zero. You might forget a decimal place, right? So whenever you're doing mathematics, it's really important to keep focused on the problem. Do the problem. Once you're finished with the problem, then relax your shoulders and look up and then attack the next problem, right? When you're doing a problem, don't push yourself to a level where you've been really tight for like six or seven problems and you're getting fidgety and you have to look away during a problem and then in the middle of it and come back to it, right? That'd be too big. Yeah, and by the way, lonely piggy, with multiple choice exams, here's one trick, okay? Go through it, right? Any questions you don't know, just circle them. Like for example, if, you know, these are the questions, one, actually I won't circle it because you want to circle it to know, right? So you've got question one, two, three, four, five, et cetera, right? Let's say you're doing this, you know, you've got question one, you've got question two, question three, you're not 100% sure, move on, just circle it. So on the scan back, you know which ones you haven't answered yet, right? And it might be a scantron. If it's a scantron, be really careful transferring your answers to the scantron, right? Don't transfer your answers if you've got any gaps in there yet, right? So let's assume you didn't know what the answer was, question three. You did question four, you didn't know what the answer was for question five. Let's say you continue to do this, and there's like 50 questions, right? Let's say in the 50 questions, you have five questions that you didn't know the answer for. You do all 50 questions, you have five questions you don't know the answer for. You go back to them, you still don't know the answer for. If you're going to guess on them, guess the letter that appears the most and all the other ones you answered. So in all the other questions you've answered, which is there's 45 questions that you've answered, right? If B is the one that appears the most, answer the five B, okay? Right? Whenever you're reading a math problem, read the whole problem first. And then when you're transferring the data over to the piece of paper, let's get this focused. When you're transferring the data over to the piece of paper, and then on the second read transfer the stuff over. Again, you're on a time crunch, so see how it works.


Welcome back and it's time for our first heart topic. Mining used to be a big deal in Nigeria before we discovered oil, the black gold, in 1956. Well, upon the discovery of oil, Nigeria abandoned not just mining but also agriculture and now about 90% of our foreign exchange revenue comes from oil, the black gold. An ugly trend that the new Minister of Solid Minerals Development, Dr. Delia Lake clearly wants to reverse by targeting 50% GDP contribution from the extractive industry and giving an ultimatum to illegal miners. Well, Mr. Bolajon Logiade, Public Policy Analyst, Lagos State, is my guest as we take a look at this morning. Good morning, Mr. Logiade. Good morning to you. Good morning. Nice to be on the program. Great to have you join us again. Good morning. Nice to be here. Great to have you. Mr. Delia Lake revealed his seven point agenda a few days ago and it includes comprehensive review of all mining licenses, surveillance task force and mines, please, among others. You listen to him as you address the press. A right in the step direction, would you say? Very much so. I guess we're waking up gradually to some of this issue. We have been too much focused on oil and gas for a long time, if not much of gas, but predominantly the crude oil. Meanwhile, all these other, the solid minerals are there, but they don't receive the right level of attention. So because we have not focused attention on it, a lot of people have abused that space. Foreigners have come in and plundered, you know, they've come in and they've plundered solid minerals and they've thrown us into environmental disasters across the length and breadth of this country. All sorts of risks we have been exposed to without making money. Most of the money we're going into private pockets. Well, his gut is what cut out for him, considering the collaboration between politically connected Nigerians and these foreigners. You've talked about 17 Chinese men were arrested in Oshun State in May of 2020 for illegal mining. Some states in Nigeria, some of the newest warning governors have also banned mining activities in states like Eboni, Oshun, Enugu, Khrushcheva, Tareba, etc. Well, the miners' association of Nigeria are kicking against the ban on mining activities by some of these states claiming it's illegal for them to do that. So Delia Leca has got his work cut out for him. Chuck Astru, what you think he may have to do to be able to muzzle through and give us what we need from that ministry? Hello, Mr. Alojade. Okay, the right response is actually not to ban mining. Hello. Yeah, go ahead please. Can you hear me? Yes. Okay. The right response is actually not to ban mining. But if we do, like some states are doing, it should just be a temporary measure while we articulate how exactly we intend to approach the issues of mining. It has been a largely unstructured space. Foreigners will come. They partner with a few high, high-amity in the society, including some of our political leaders. And then they take all these gemstones and share the profit with nothing to the people. So one of the things that need to happen is that we need to, number one, harmonize the policies at the state level with the federal. So, yeah, the laws are clear. What is the role of the Paragoman and what is the role of the state, as well as the communities where some of these gemstones are. So we need to be able to articulate the policies so that we are speaking with one voice. And we are not confusing the mining market about the opportunities that exist. Then once we have articulated our policies properly, then we can structure that space and ensure that the concessions follow the law. If the laws around the concession of mining is not robust enough, we need to step into that space and make it more robust and implement those policies and laws as stated so that the resources that belongs to Nigeria will be to the benefit of Nigeria and while we mine these resources, we will also articulate the environmental issues. It is not enough to just want to take from the environment. We must preserve and protect the environment as well as deal with security issues that have been associated with a lot of mining sites in Nigeria. Okay, well, this has also brought to the fore the issues of land use act. You find that in the south, the oil belongs to the federal government. I mean individuals who mine, who have refineries, are treated in the way that... You've seen all that's been playing out, which has led to people from the south saying there is such imbalance. You know, if in the north, the resources there are left for individuals as it were, as we've seen, which has given bread to a lot of illegal mining. Why is it that in the south, people are easily clamped down? I don't think that the laws are discriminatory, south versus north, because mining is also taking place in the south. Well, and don't forget, we have the federal ministry that you pay to mine. It's at the federal level. So that is to show that the federal government still has a control over mining activities with a handshake with the state and the communities where these resources exist. So what we have not done, in my opinion, is that we have not put a focus on it unlike the oil and gas space where all our emphasis has been for decades. When we exited all those mines and the coal mines some 50 years ago, and we have discovered oil, we just let all those mining affairs and focus on oil. Oil was good. We were able to make a lot of money from oil and nobody cared about mining. It is now that oil is becoming a challenge. Oil being about 90% of our foreign exchange earnings, oil being dependent on so many factors, it is now that we are beginning to wake up to pay attention to mining. So I don't think it's an issue of discrimination. I think it's more of an issue of we've been used to oil for 50 years. Now, because oil is absolutely no longer enough and it is also a dying resource, we are beginning to now pay attention to solid minerals. So we should focus on it and make it work for us just like we have focused on oil for so long and made oil to work for us. For a very long time, Nigerians have cried about the illegal mining activities in some of the states and wondered why some states' governors appeared to have turned the other side, looked the other way while these illegal miners went on and had a few days and also looked at the cheap labor, the cheap labor that these illegal miners were able to have in those states. What do you think that the NLC, because I think we should bring in NLC here, should be doing with regards to the people that are used or have been used in these sites, these illegal sites across the states who have been unjustly used if I could put it that way? I'm not so sure that NLC has delivered in court. I don't think they are able to deal with this matter. The way things happen in those mining areas, a lot of insecurity issues are involved. There are not places that you just jump into because you said you are lipo. Are you joking with your life? These are people who come to mining sites with military and police and security present. Private security and public security into those particulars. They have a concession and the concession is from the government. It goes way beyond what labor can handle for now. Of course, because labor is involved, workers are involved, I believe labor by the side is supposed to start to agitate. But the nature of those mining sites, as it were today, does not exactly lend itself to what labor can readily intervene in. Number one, the communities themselves are involved. The communities where those resources are are involved at the level of the tiny amount, what are called peanuts, that are handed over to this community. We are talking of poverty. People who have never owned 100,000 naira of their own at the time having a million drop on their laps, they take the more million and then they collaborate or they more or less support what is going on. I've seen instances in which miners come to a village and offer the village a new palace and look, we'll build you a befitting palace. This one you are living in, it's not good for you. And they did that kind of a traditional ruler does not understand what he's giving away for peanuts. So the community are involved on one side. Political leadership is involved. We have spoken about certain states where it seems as if the governor looked the other way. Why do you think the governor in those things are looking the other way? It is because these are also the elite or members of the elite that are involved in these illegal activities. So the man is not going to pay attention because he himself is involved. That is why the current direction is so much welcome. It doesn't have to be attacking in nature. We can call in all the stakeholders have the right level of discussion and articulate the policies to make these resources beneficial to the Nigerian people. Well, the miners association of Nigeria what do you think should be done about their cry, their outcry against the banning of these some of the sites across some of the states where legal mining has been taking place. They have quoted some laws, some aspects of the law as they kick against it. They are a critical stakeholder. So when I speak about engagement they also have to be in the mix of all those engagement. Most of the mining activities that are going on in the country are largely unstructured. People are privileged so they've got some concession, they go into communities and plunder the community, giving people pay not, don't care about the environmental issues. That cannot continue and the miners association within itself will also begin some sort of self-regulation before or as part of the entire gamut of reinventing that particular space. There must be a regulator monitoring is critical. What are these miners doing in the mining site? How are they treating the environment? How are they treating the environment? While the regulation from the government is critical, the issue of self-regulation from the miners themselves or the miners association is also very important so that the miners association on one side are self-regulated and then there is regulation from the government so that we can have a same environment. The miners must consider some element of self-regulation. What we have right now in the mining site will embarrass anybody who loves the environment. It is horrible. So some element of self-regulation but self-regulation would not be enough. Government has to make sure that the regulatory environment must be stronger. It is part of this policy articulation that is devastated. When you take from the environment you must also be ready to go back to the environment. Protect that environment and ensure that it is not just you taking you also give it back. The way the workers are being treated is horrible so government also has a role in that as well as the miners association. So when we talk about engagement that needs to happen those engagement must also involve the miners. They are a critical stakeholder that must reform their way in how they approach this resource mining as well as how they treat the environment and the people. The way the workers are being treated as you have just rightly alluded to is horrible which is why I had mentioned earlier they need to have the NLC look into this because not just these miners these workers who are working for these illegal miners and even the illegal miners being treated shabbily you find that oftentimes some Lebanese and Chinese corporations come into this country and treat their Nigerian workers shabbily in the most dehumanizing way possible and they keep getting away with it and I wonder what is Labour doing right from my days as a youth copper in Port Harcourt. I've heard such stories and it's continuing all to today. Yeah, like I said Labour must play its part but I also understand for example we let NLC walk into the good minds of Zampara to go and carry out say a picket where there are bandits left and right where there are guns firing and aircraft all over the whole place. It is most unlikely that that would happen. But it could go with the police the monitoring police they could go with the monitoring police and the surveillance task force and the minds police which have been set up I understand we already had them before so perhaps this is a kind of reinforcement that the new minister is talking about so if Labour was interested in doing anything about it they could go with that monitoring task force and the minds police force. You see I still prefer that the strengthening comes from the government the power of our security the miners side themselves are heavily policed sometimes with military people and private security operators that the miners themselves are hired to come into that space so the the true way that can be effective in my opinion is that the government in its might which is what I think the current minister in charge is trying to to try because all these things that you were talking about have been there so the question is why has it not worked but if government at the centre have decided to put a renewed focus on it and the minister is serious about implementing what he has said the way he has said it things will begin to change things will begin to change everybody will know that there is a new sheriff and that all the nonsense and shenanigans of the past will not be allowed it is on the wing of such situation that you can see the NLC become effective and rise up to their own responsibility and the expectation that we have of them. Issues of safety are the mind for example it's a very serious matter people are dying in the mind they do collapse and kill people but in the course of oppression and even in the abandoned minds who is paying attention to that labour must do its part but if labour is going to be effective, government like the current minister is trying to do we need to step in right there powerfully and possibly come there while wielding a stick and make sure that the laws are obeyed anybody who disobeys is punished accordingly it is very important that we do that and that create the right environment for even NLC to begin to step into the position you know as we talk about this I am reminded of the blood diamond and if we are going to move forward would you suggest that some who have if not all who have enjoyed the wealth of this illegal mining who have made billions of dollars from this illegal mining would you suggest that this new minister goes after them to get them to account and also for the damage that they cost to the environment the illegal mining and then justice meted out to the Nigerians working for them it would have been nice but I am not so confident that something like that will happen and the reason is that the issues around the environmental issues surrounding mining activities is not peculiar to to solid mineral we have seen it in the oil and gas space for decades and the question I ask is how have we been able to deal with environmental issues in the creeks in the creeks of Nigeria in the Niger Delta how have we been able to hold people to account including multinationals who have plundered this environment and left them in disastrous situations there are local companies too who have done the same thing in the same Niger Delta how many of them have been able to hold to account I remember vividly what Obama did with a massive spillage by mobile during his turn as president mobile almost left that environment by virtue of the kind of punishment that was meted out to them in Nigeria we are yet to see that so will it now happen in the case of solid minerals fingers crossed I am not particularly hopeful that it will happen but if it happens I actually look forward to being disappointed when it starts to happen solidly I also say that the 30 day ultimatum given by the minister to the illegal miners is way too lenient do you share that opinion I didn't hear that I said there is a school of thought that 30 days given to illegal miners by the new minister is way too lenient that he should have just gone right in immediately immediately may also not work out there are equipment all over the place the mining equipment are there there will also be certain discussions that need to happen so I think 30 days is okay you know but then 30 days also allows the government to prepare its own roll out the monitoring team that will go out and enforce the illegal you know the law against the illegal activities you have to prep I mean you know that kind of a task force you have to prepare the resources for them to be able to do what they need to do you have to work with the security agencies to be able to enforce so it's not actually something that you can jump into and make happen in one week or two days 30 days is a very good notice get out of there if you're very illegal and if you're still there after 30 days then whatever you find you take it well thank you Mr Boulangho for your time on this very critical issue that we're taking a look at this morning thank you Mr Boulangho public policy analysts has joined us in Lagos to take a look at our first hot topic do stay with us we'll be right back


My name is Matthew Sanders, I'm with the State of Louisiana's Office of Community Development. I conceived and for the past several years have led the LA Safe process in our state. I believe resilience means the adoption of a philosophy, a way of thinking. I think it's taking an array of inputs that are at hand and those that we can anticipate in the future and using those inputs to define what our development patterns are going to look like, what our society looks like in light of current and future risk that we can anticipate. LA Safe is a planning, policy development and now project effort that emanated from the National Disaster Resilience Competition. The Office of Community Development applied on behalf of the State of Louisiana to secure those dollars from the federal government and LA Safe was one of the projects that was funded therein. Once we received funding for the initiative, we, along with our partner organizations, have led the effort in a six-perish area throughout Louisiana. I think in Louisiana it has changed the conversation in how we think about flood risk in a couple of different ways. First and foremost, we understand that we have to think about flood risk holistically. It's not just surge flood risk from hurricanes, but we also have to think about riverine flood risk, flash flood risk and insofar as we can compile that information and disseminate it to the public, we have an opportunity to think about all of the consequences therein. What happens to housing stock? How do economies change when populations move away from risk to places of relatively lower risk? How do we think about transportation networks? And so we took an approach that is focused on the disaster risks inherent in Louisiana and we opened it up to a more robust conversation about a total development pattern. I think the LA Safe planning process is different than what most jurisdictions have undertaken and that as we talk about climate risk and specifically flood climate risk, most of the planning efforts to date have focused on large-scale, hard infrastructure. And while I think we understand the utility for large-scale, hard infrastructure, what we've done with LA Safe has really opened up the conversation to a more holistic planning process and more comprehensive planning process than what has been seen in the past. Well, I think LA Safe can serve as an example to other locations in two ways. One, I think it should illustrate what you can do if you have good information about current and future disaster risk so it should provide some illustration to other jurisdictions to make those investments to understand what their risks look like. And then I think it can serve as a blueprint for how that type of information can be disseminated to the public and how a holistic planning process that is community-centered can take place and be successful. So federal programs and policies have been extremely beneficial to the LA Safe effort, namely the National Disaster Resilience Competition in and of itself provided a catalyst to disaster-affected regions to really think more creatively about how they were going to approach those disaster risks now and in the future. And I think the federal government has a unique role to play in incentivizing that type of creativity at the state and local level and that really can be a driver for innovation now in the future. We have a series of 10 projects that are all in various stages of implementation. The physical projects should all be under construction early next year. And then from there, who knows? We'll see what happens.


You guys are all very orderly So Byron, are we are we recording shall I go? So we wanted to welcome you to the first Bay Area wiki salon and the wiki salon is a concept that I think people in New York and DC have have kind of formalized recently where there's just a monthly Regular get-together of people who are interested in wiki and and it's it's an idea that you can really attach just about anything you want to And I used to do something similar to that up in Portland before we had a name for it You know lots of people get together and talk about wiki. Sometimes we have presentations Sometimes we might Have shared editing events where we work on articles together Sometimes we might just have spontaneous discussions So we want for this first one we wanted to bring in some interesting speakers to kind of get us started So we can engage with some ideas and sort of some conversation starters and get us thinking about some stuff But in general We'll also try to have a bunch that are that are more open and freeform than that so as a thanks for coming and helping us get it started anything you guys want to say before I Keep going My name is Wayne and I'd just like to invite you to come back May 25th for the next one and to spread the word Yeah, and I would say it as far as the dates. It's always gonna be the last Wednesday of the month is what we're planning and Bear with us if it seems a little, you know freeform disorganized We're hoping that one of the things that when I go to meetups I always like hanging out with people and so sometimes the meetups don't give you enough time to hang out with people This is gonna be a meetup Which is gotta hopefully some time to hang out get on your laptops and look at some articles understand what Wikipedia editing is and all about and So yeah, I'm excited to see everybody here And I think I think I may be neglected to say my name So this Wayne Calhoun over here Ben Creasy, and my name is Pete Forsythe and also the three of us have have Brought the food and drink for you tonight. I appreciate some of you also bringing some to supplement We got a few more people here. So it's nice to know we have plenty to share with with some reinforcements In general, I I think we actually didn't put one out yet, but we were we were thinking might be nice to put out a Jar where you can optionally contribute some money and that way will have sort of a rolling fund to be able to have beer and snacks And also we could do if you want to contribute some through PayPal My PayPal account is available for that. I'll put something up on a sign Before we're done so that we will be able to kind of you know always at least have something to share And you're always of course welcome to just bring food if if that's preferable and There's oh very important no obligation at all to me to all of us I think the important thing is is that you come and that you have a good time So if means are tight, please don't in any way feel obliged I Want to thank a number of people that have helped Make this possible first and foremost the the Wikimedia foundation itself for offering us this incredible space As I think you're gonna see the AV setup here is Very cool for this for the kind of thing that we're trying to do and obviously just a pleasant space to hang out in In particular Byron in the back is running our AV. He's doing it on short notice Just got roped into that this afternoon. So thank you very much for that Rob Lanfeer and Steven Laporte Steven where'd you go? In the back there are two of our steadfast staff hosts Sandra Mikulski sitting next to Rob over here has has stepped up Not once but twice for a similar event for their 15th birthday to help us get everything set up By my good friend Reverend Phil also lost track of Showed up literally on my doorstep last night and kind of helped me get prepared for all this today So I really appreciate that. I usually am helping him organize events. So it's nice to do a little role reversal And of course our panelists who you're gonna meet when we get started So I'll leave the names until we can actually put a face with the names a Few logistic points if you want to get on the Wi-Fi there is I don't remember the information It was it's on the so the the network is WMF guest and the password is The number one and then everything is lowercase edit can make a difference one edit can make a difference We also have a hashtag for social media is BAWS right Bay Area wiki salon. So hashtag BAWS if you're on Twitter or other social media The bathrooms are near where you came in just past the just go left on the way out here And I believe there's actually given our topic tonight I believe Craig no new mark contributed to have a gender-free a gender neutral Bathroom here in the office a while ago. So that's kind of a nice topical option. Don't don't worry too much about where you go if you got to go and I think that's oh and and and also we very much want we very much want your ideas about What to do with these events? So if you have always wanted to get people together to work on an article about Model railroads or if you have a speaker that you think would be really interesting Please speak up We probably won't do a lot of planning in the events because we want to leave space to just kick back and relax Most of our planning is going on on meta wiki and you'll find it if you go to the event page and click on the talk tab You'll find links to where we're where we're doing our planning for future events. I think that's about all I've got for for intro Any questions any comments before we get started with our panel, okay? The sides will be so Byron if we I guess Maybe we do want to leave some space to see the sides a little better if we're off to the sides like this Are we on camera or okay? Okay