Welcome everyone to the minimalist death room for the second time we're organizing this and You know so far we've had some great talks. I hope I can live up to that expectation So Lisp is the second oldest language used in use today the oldest language is Fortran and I just yesterday yesterday there was a Fortran to LLVM talk, so that's also still alive Fourth we also had a talk which is quite old early 70s. I think yeah Small talk is also quite old. So, you know These old languages seem to seem to stick somehow, which is great So, yeah, I've I've went through many phases in my life I know I've started program in the early 80s and went through you know from Pascal to through C++ to Python Ruby, whatever's elixir Scala D and I still like Ruby and I still like D so What about Lisp? So the first one of the things I learned is that you know the top 2% of the programmers in the world They they can program in Lisp. Have you heard about that statistic? So of course when you want to be a top 2% programmer, what do you have to do? You have to learn Lisp so that was an incentive And then I ran into a number of projects including GNU Geeks, which is a package manager I've written in Lisp and you know so slowly I started to And it's surprisingly easy to learn, you know, you can teach a youngster Lisp probably in an hour. I think yeah The basics so that's that's great But I also discovered the Lisp is very much a Ruby or a Ruby is a Lisp really, you know And I met Matz who's the creator of Ruby two years ago and I asked him, you know, say How come Ruby is so much like Lisp and he says yeah, actually people in the early days called it Mark's own Lisp instead of Ruby Yeah, so there's a lot to share then So also Lisp is a lot like Python or Python is a lot like Lisp and you find these things out but There's something else Lisp is everywhere and I'm gonna talk about that So Lisp you can find in Emacs You can find in the education great programs AutoCAD in the early days use Lisp, GIMP, Julia, Julia was originally written in Lisp, you know that So there are Lispers there Logic programming, mini-cundron Clojure in the last ten years has, you know, wedged itself into the business market Gnu Geeks, of course, is very much popularizing Lisp and and pushing guile to its limits and that's the next talk Never Gnu mess Jan was talking about just now. Yeah, there's a lot of Lisp in there and the shell anyone heard of shells Lisp there we go, so In a nutshell your most broken language language rights and then braces and then a parameter Lisp, you know, the braces are just on the outside. There's all you need to know So when people say there's lots of parenthesis in Lisp, you know And where most languages handle scope and you know with curly braces in the C-style syntax and you have imperative assignments, right and then you do something like Concatenation in Lisp you write something very similar just looks a little bit different, you know So you start with a with a brace and then you assign the parameters Right, and then you do something with it But what you can see is that it's very consistent, you know Because functions are always started the first position in the brace So that's how they get evaluated and then you get a list of parameters And even for assignment, you know, it's really a function Yeah, which has a list So and the other thing is that most lists today they allow you to also use square brackets, right? So as long as they match up you can you can exchange them with with the braces But interestingly it introduced a scope and one of the things I found out quite late, which is embarrassing Is that and this is really beats other languages, you know, I think to the core is when you run Lisp in a Rappel, yeah, so You can you can just cut and paste the inside of an expression, right and and feed it to the rappel again Yes, so if you do debugging, I mean try that in Python So here's a famous list. It's it's running in a in an editor and Here's an example. Yes, so Emax is written in Lisp essentially It has a very small C core that runs the Lisp engine Which means that all the configuration is is is done in Lisp, too Yeah, so once you get used to the list syntax, you don't have to relearn anything what you only need to relearn is how you know Emax has created its world of of of Functions or procedures Which you just can call Yeah, so I wrote a function at some point that I wanted to copy the line above and I probably did it in the most Inelegant way Yeah, because I wasn't really into Lisp then But you can essentially write a function that says, you know, take take the cursor position Copy the line above it's injected back into the into the text buffer. You can even inject into a different buffer if you want And this is what it looks like, you know, and it starts it starts to look familiar now And then when you have written the function You can bind it to a key Right and this in this case is control backspace and I see if it works Yeah, right, so I wrote this language extension myself, you know, it's a really minor one But I think it just shows the power of of of using a configuration language, which is also programming language So Emax is for programmers. So that that point I really would like to emphasize, you know, in fact, I I use Vi Vim for almost 10 years I started with Emax then in a you know In a in a in a in a in a mind melt I went to Vi and then 10 years later, you know, I went back to Emax And the real the real thing is that because this is such a configurable editor. It becomes a great programming platform, too Yeah, so programmers love an editor that you can program And that's what Emax is Racket. So this is another Lisp Which is really making Lisp popular again And the record has a record that comes with the shell is called trash Yes, it's an unfortunate name, but there you go And I just want to run quickly through it because record allows you to mix shell commands with Lisp commands, which becomes very interesting So you can install record. I'll share the slides And then you can say something like Require some modules, right? And then hey, that's a that's a shell command. See that cat, etc. hostname And you can pipe it into a Lisp procedure And that binds me to another one. So what you can do is say, you know, turn some trimmer string Or you can say Let's see here's a mixture again Define hostname is cat, etc. So you have to embed it shell again, right And do some function operation on it And then you can just run a plain shell script where the parameter is actually lifted out of the Lisp evaluator Right And that's that's already pretty cool But you can also do things, you know, you can't even fathom doing in a shell like parsing jason, parsing jason So this is an arrest endpoint which returns a very complicated jason record And I can actually I can just, you know, fetch it with within within the shell using a Lisp expression And, you know, the record in the first stage of the record is a hash is a dictionary What are you trying? Hey, Alastair, how are you? All right Is it not the blue one, the black one? Yeah, try Ready for lift off Ready for lift off? Yeah, so you can do something very complicated and then out of this jason record you get, you know, this string So in a shell script, essentially you can do complicated things and you can even do, you know, you can use SQLite as a back end And, you know, push some state into a SQLite file database Try and do that in a shell Another thing is, you know, the shell scripting program and probably most of us get caught at this at some point You know, the shell, when you pass a list of words in there, is it a string or is it a list? Yeah, so here's an example Here's the shell script that I used to upload some files to my web server, sorry, to my mail server Yeah, and you can see that the file name has spaces in it Okay And when I actually run the shell, the script which simply is shell and then using the expansion string star Of course it breaks because it starts, it thinks these are all different files, right? Anyone bitten by that before? Yeah, so the rash version is that you start the shell And you can parse the command line using current command line arguments And you can see if you use single quotes, it actually sees it at words But if you use double quotes, it will see it as a string, sorry, as something with spaces So to write the full script, you could do something like this Where you say, okay, we're going to run a system command, the system star Calls the rsync and plugs in the fn, which is coming from current command line arguments So this is a lambda, and in lambda the actual parameters to the call are listed last Which is counterintuitive for us Ruby programmers But Racket comes with a nice facility, where you can say for a list, function name, that's the parameter Fetch it from the command line and then run the command And this starts to pretty much look like Ruby to me Yeah, I mean with a little bit of syntax And then you run it, it works, right? As it should, skip this So here's a more full rash script where I just show that you can create a loop So the student file lists student names with spaces And then I create a name, removing the spaces And then I copy the file, the text file to the output file And then I run set, hey, and this is again just a shell command essentially Yeah, and this is also a shell command So what you see is you can mix in a loop, you can mix shell commands again Which have the normal shell syntax So I think rush is pretty cool, and for guile we have gash If we could do this type of thing, Jan Really interesting So there's more reading here, you can read on racket And why is rash so interesting?  New guile I'm starting with hacking guides, great That should be the last one So the new geeks you've heard of before if you were in the room Is a package manager, it's a functional package manager And it's essentially written in guile, which is a lisp again There are many flavors of lisp, and this is one It's a scheme And You know, when you install something with geeks on the command line You can do something like geeks package, install, racket, image, racket, mode And then I'm going to put it somewhere, that's what it says And then you load the profile, which is the number of environment variables And then you can run the program, which is in optrack, it's bin, racket And it will give you a prompt I should have given a guile example anyway So Geeks is written in guile, so we need to install that first And I'm also installing some nice packages that go with it, emacs, emacs, geyser, or geyser And par edit And when you do that You can Do something Like this I have a pipette as well There we go You can start the rappel Yeah, with the Where the meta command x shell and then run geeks rappel So geeks rappel is really just a command line tool And it drops you straight into a lisp rappel And it allows you to interact with geeks So the geeks package manager And here, for example, we say, okay, use these modules, use geeks Use GNU packages scheme And then tell me about the racket package And it gives you information on the racket package Including which file it sits in, GNU packages scheme And the line number So you get this facility where you can actually interact with the geeks package manager Through lisp And you can query data, you can say something like package version racket So let me try that if I It's always dangerous to try things on the command line What did I say, racket? So here's the package thingy And then I need to say, for example, package version racket And return to the version that's installed And there's a lot more to that So you can get all the information that's in the package manager And if I show you what the package manager looks like That's the wrong one Too many things are open now My poor small brain So if you have, for example, here's the package definition in geeks You can say define public, which is the package name Which is called Ruby connection pool And this is a Ruby gem It's a Ruby package that comes with Ruby And essentially say this is the name, this is the version This is where we fetch it from It comes through Ruby gems So it's a Ruby gems URI And you can see that the Ruby gems If you set it from git, it would show a git URI So we have a high level abstraction here for Ruby gems The shaft value just says this is what the tarble What the shaft value should be like So you don't accidentally get another one And then the build system is the Ruby build system Then it has a native input So that's the dependency, it depends on bundler And then you have the synopsis and the description So this all describes one package in geeks Which is concise, right? And it's also a lisp again So you can understand it now, right? Even if you don't, even if you have this one This 10 minute introduction on lisp that I have given Anyway, so if you query the data that was on the rappel You can actually get this information that was in the package definition You can just see it here And do something with it You can also interact with the demon I'm not going to run it now because I don't have that much time But essentially you can open a connection with the demon Which we call s here as a convention Or store or geeks demon So there's not much of a convention And then you can What we call a package derivation Of the package that you want to build In this case we're installed, this is Ruby And a derivation is sort of the lowest data representation Of a package So it includes all the dependencies and everything And then you simply say something like derivation Sorry, that's what it returns This is how you fetch the file name of the derivation And in this case we want to build it So we say Build derivations With the demon And then take a list of the derivations In this case it's a Ruby derivation Which was fetched here So if I run that it should install Ruby Which is always a bit dangerous Let me try and kind of paste that Live dangerously when you give a demo Yeah, so it returns true because the package is already installed Yeah So it doesn't reinstall unfortunately Very convenient for demo But that's it, that's all there is to it How many? Nine, okay, that's cool And then we have a concept called the store monad So when people talk about monads They usually think about things like Haskell functional programming languages You can also do this in Lisp Five Oh, thanks Yeah, so And the specific monadic functions Which avoid you to reference the demon Or the store or the connection every time So rather than the earlier Here we explicitly had to set build derivations s And then something Yeah, so here we can just say package derivation ruby And you don't have to relay to the I mean the monad carries the definition of the store with it So you don't have to reference to it again And this is another way of simplifying the code Because otherwise you would have many references to the demon And that's actually not necessary So to capture it all You know, with Geeks the source code is a documentation I think And we show some high level functionality for building And exploring packages And the fun thing is you can also use a debugger So you can actually step to When you build something you can step through the code That is the package definition and what it does with it And it's all the unified list syntax So your distro here is a scheme library for hacking You know, through the Geeks Through the Geeks APIs And here are some links which are available I'm going to skip this one So just like Emacs, Geeks is for programmers So once you master Lisp You can do anything really So I'm going to quickly touch on another Lisp Which has become very important in the business environment It's Clojure And it's a little bit I mean the Lisp people in general When they frown when you mention Clojure It's different from most Lisp But I think it's I can't say it's superficial But it has very interesting ideas Conceptually it's a different beast altogether But it shares things with the other Lisp Including the syntax It takes a little bit of some freedom When it comes to saying Rather than writing Where did that go? I think something disappeared Oh no, that's probably the same So that's a list, right? But this is a vector And a vector in the other Lisp Or at least in scheme would be written like this And this is a hash value or a dictionary And this is what it looks like in the other schemes So there's some differences And I think it was This is meant to make it nicer For people who are coming from JavaScript, Python, Ruby and all that But it's the same thing In fact underneath it will return similar values And then Clojure has A lot of ideas around functional programming Including immutability And shared state handling Which are all important And it compiles to the JVM Which is an advantage if you like it And it's a disadvantage if you don't like that And Clojure Scripts Which is also Clojure translates to JavaScript So essentially you have one language That can target either the JVM or JavaScript And I think in a business environment That can be pretty attractive But there's not to say that This is the only way to do things You know, because there's a For example, BWA scheme Is a JavaScript interpreter That runs in the browser When you use that You can do something very simple like this Which is HTML And then you script The JavaScript interpreter You pull it in And then you can just write scheme again Which is a very interesting tool WeeScheme is a record ID That runs in the browser So that's another browser interpreter PanScript takes a slightly different approach It's a JavaScript generator So it's more like Clojure Script And Spock is the chicken scheme To JavaScript generator So these are all projects That can do pretty complicated things And it all originates on the fact That writing a Lisp interpreter Is not that hard At school, at university At least maybe not the last 10 years Who has learned to write a scheme Or a Lisp interpreter in school See? Yeah, that's a few So it shows you it's possible Anyone wrote written C++ interpreter here? They also exist But they're a very crazy beast So Spock can compile to either C or JavaScript And it's a chicken scheme And I'm going to wrap up now Because the take-home message I think is that Lisp is one Or maybe many languages that serve all I think that's the key thing And there are many great Lisp Lisp is easy to learn Lisp is everywhere It can be used anywhere It's for newbies and gurus alike In my opinion But what is really important In this stage of millennial angst Is that you don't have to worry About what language you have to learn After this There are so many people That come to me and say Should I learn Rust? Should I learn Python? Should I learn R? Or whatever You should learn them all You probably You're over it Thank you Any questions? Yeah? I noticed at the Geeks Rappel There was a lot of answers Don't assign numbers Does it mean it saves all the answers? Yeah So the Gal Rappel saves all the answers That's true


Hello there! This is Mr. P. On today's lesson, we're going to take a look at an opinion essay. After this essay, I suggest watching lesson 1, 2, 3 and 4. So, first things first. Introduction. Essential questions. What is an opinion? What is an opinion writing? Where do we see examples of opinion writing in our everyday lives? So, first question. What is an opinion? According to dictionary.com is a view or judgment formed about something, not necessarily based on fact or knowledge. According to Merriam Webster, a belief based on experience and unseen certain fact. So, what is an opinion writing? When you need to write an opinion essay, you will be trying to convince or persuade the reader of your own opinion or belief. You'll be naturally taking a position for or against a topic. Examples in our everyday lives. We have billboards. As you can see, we have books or movie reviews. And commercials or advertisement. So, what is the purpose of opinion writing? For example, to support a cause or create change or call people to action or persuade people to agree with you. So, let's go over some examples. Purpose 1. Support a cause. For example, please donate money to save penguins. Poor penguin. Purpose 2. Create change. For example, we should be responsible for our environment. Purpose 3. Call people to action. For example, book your adventure trip now. Purpose 4. Persuade people to agree with you. The best kind of food is sushi. So, parts of opinion writing essay. We have an introduction with a thesis statement at the end. Then we have a body or two or three body paragraphs. And then we have a conclusion. At the beginning of a conclusion, you need to restate your thesis. So, for this, you need to watch lesson 1, 2, 3 and 4. So, what makes an opinion essay topic successful? Well, you have strong feelings about a topic. Or you have prior knowledge on the topic. And you can easily find support for your arguments. So, examples of good topics. Should students wear uniforms to school? Should students be allowed to use translators? Should students be allowed to use smartphones in school? How much homework should be given daily? Should smoking and vaping be banned? Everywhere? Your turn. We use search engines every day to find quick information. Are they making us less smart? Explain your opinion on whether Google is making us less intelligent. Write one paragraph. Be prepared to share. Hmm. So, I hope you enjoyed the lesson. If you haven't subscribed to my channel, please do. If you liked the lesson, click on the like button. And you may share the lesson if you liked it. Until next time, bye-bye.


Hi everyone, in this tutorial, I'm gonna be showing you how to create secure random numbers in Python language. In order to do that, we're gonna import Secrets module. If we want to create secure random numbers, which are hard to guess, we're gonna use this module. Random numbers created with the usage of this module are very hard to guess. Humans and computers can't guess the next number. Let's say that we want to create random number between 0 and 100. We're gonna use random below method and we're gonna provide upper bound and this function is gonna return a random integer number in the range from 0 to 100. Let's print this random number. Let's run this code. At this point, secret random number 3 is generated. So use this module and the methods from this secret module to create strong secret numbers. That's all in this tutorial, don't forget to subscribe to our channel, see you in the next tutorial, happy coding.


Let us have a look at how we can use the methodology for sizing of an indoor airship for a practical example and for that I will take you through a small tutorial. So we are going to follow a particular color scheme in this presentation. So anything that you see highlighted like this in yellow color means this is something that we this is something very out to pay attention because that is something new in the tutorial. The general instructions will be given in black color. The specified values also will be in black color. The values that we assume for some parameters are going to be in this blue color. The calculations to be done by you are going to be indicated in red color mostly by question marks and there will be a pause button where you are requested to pause the video, do the calculations and then continue because we will give you the answer after that. If you do not pause the video, if you continuously watch the video without pausing, you will not be learning anything because in any design exercise you learn by doing things. So we want you to learn, so therefore we want you to do these calculations with us, stop the video when you see the pause button or the red color, do the calculations and then compare with your numbers and then finally whatever values we calculate are going to be shown in this dark blue color. This is something which I have already shown you in the previous lecture about the motivation. We also know what is our problem. We know that we want to design something for capacity of 250 grams payload less than 4 meters in length and it should be electrically powered and look like a typical airship and these are the requirements which have been discussed in great detail. So if you have not watched the video regarding the sizing methodology, I would request you go back and watch that before you do this assignment. This is something new, input data and requirements. So what is the input data payload to 50 grams and let us assume that you want to design a airship which can fly at around 8 meter per second, quite a good speed. But we want to limit the endurance to 15 minutes and the calculations will be done under ISA conditions at sea level. So you can do these calculations at conditions which are appropriate to the place where you are flying the airship. What are our requirements? We want length to be less than 4 meters, we want volume to be less than 1.4 cubic meters because we want to use one cylinder of helium or hydrogen available in the market at 7 cubic meters about 4 times. Okay. The gas could be hydrogen or helium, we will see what happens with both of them and we want to go for 3 motors, trimotor configuration, one motor on the back for yaw force and one for forward thrust and one on down for giving us thrust vertical force if needed. This also I have already covered that we need to understand. I will skip this, let us go to the methodology. This also you know this methodology I have explained in detail. So we are going to envelope design which is the first thing is to assume the envelope length. We assume the length of the envelope. So let us say it is 3.5 meters, why? Because maximum limit is 4 meters I just said let us take 3.5 meters. First thing is envelope shape selection, you have already been told that there are many considerations okay but and also I mentioned to you about the standard shape which are available and also we have selected the envelope profile to be NPL for this particular exercise. Now for NPL this is as I mentioned to you L by D is 4. Now you can get numerical expressions for surface area and volume. If you define a parameter Xi which is the max diameter upon maximum length. So here D stands for max diameter and L stands for the total length okay. So you can calculate the eccentricity of the envelope using the formula given on the bottom and then with the eccentricity you can get the value of the surface area okay. The formula looks very very confusing, very complicated but do not worry it is not a big problem okay. So let us do surface area estimation for the envelope profile length 3.5 meters. We know that the diameter length diameter ratio is 4. So first you calculate the value of this Xi which is D by L. This is the first calculation that you have to do. So if L by D is 4 what is D by L it is 1 upon 4. Then we have to calculate the eccentricity of the envelope. Accentricity is given by this formula root of 1 minus 1.457 Xi square Xi already know as 0.25. So this is the second calculation for you take a pause calculate the number and then when you are ready you can play the video and you can compare with the number which we have calculated. Volume is given by this formula you know the value of L 3.5 meters you know the value of Xi 0.25 it is very simple just calculate the value that is the answer. Surface area yes this is a fairly fairly complicated question but remember the value of E is to be considered in radians when you calculate this number okay. So when you take sign inverse you have to take a sign inverse in radians that is a very common mistake many people do. So this is of course a very nasty formula. So I am for your ease I am putting all the numbers there and I would like you to calculate the value. So you can pause the video calculate the value and then compare with the value that we have got 7.755 square meters your numbers may differ slightly in the third or second decimal place does not matter. First cut volume estimate using the graph which I showed you last time and using this formula. So in our case the payload is 0.25 kg we put the value of payload and you can get volume is equal to payload that is 0.25 plus 0.5739 divide by 0.3093. Calculate the value please the value is 2.66 cubic meters but we got a much different volume when we did the calculations in the previous slide. The reason is that we are looking at the extreme bottom of the graph which is for payload from 0 to 20 kg whereas ours is only 0.25 kg. So actually this graph may not be directly useful for you. So therefore it is just an initial estimate. Young has gone for shape classification. So young was a scientist who worked on various kinds of airships there is one very famous series called R101 series. So he got this equation of for area and volume for a class of airships as a function of D and L. So he plotted so if you plot some existing airships like from aero drum or RC blimps you find that they are slightly higher young surface factor compared to what he has got. Similarly if you plot the young's volume factor you also find that these airships have a slightly higher value. So does not matter. Let us look at the aerostatic lift estimation. So we have the envelope volume 1.403 cubic meters we have the density of ambient air under ISA conditions. If we assume hydrogen as a lifting gas we have the gas density under ISA conditions. So therefore the lifting capacity will be obtained directly by subtracting 1.2256 minus 0.0841 we will give you 1.1415. That means for every cubic meters of hydrogen inside the balloon you can get a vertical force of around 1 kg and 140 grams. So can you calculate the net lift which is the lifting capacity into the volume of the envelope. So what is the net lift available from the airship that we have chosen of 3.5 meters length it is 1.602 kgs. That means the entire weight of the airship minus the weight I mean including the payload should be less than 1.6 only then we will be able to get lift. If we repeat the same calculations for helium which has a gas density higher than that of hydrogen the lifting capacity is lower it is around 1.0594 kg per meter cube. So once again can we calculate the net lift that can be obtained by 1.403 cubic meters worth of volume of the gas the value is only 1.486 kg. So you can see that there is a difference between the lifting capacity of hydrogen and helium. And now we look at the surface area and envelope material selection and the weight estimation. So you already know the features of an envelope material I do not have to repeat it. We also know what are the candidates available this also I discussed in my previous lecture. Let us go for specific material so if you choose a material of 65 GSM which has all these advantages it is flexible it has got low gas permeability light weight and heat syllable these are the positive features so this material is suitable. So if it is metallized nylon citric GSM area comes to 7.756 already calculated and we need to assume a 15% margin for joints and patches because you are going to join the petals you will along the length of the airship there will be some overlap and therefore there will be joint weight then there are going to be some patches to put hooks etc. So therefore you need to give margin of 15% for the additional weight of the material due to patches and joints. So therefore the envelope mass could be estimated as 15% margin included surface area into the envelope GSM. So can you calculate this value please it is 579.73 grams so close to 580 grams is the weight of just the envelope and this is the finished envelope that we got going ahead let us go to get the gondola. As you know there are several materials which can be used for gondola we want to look for a lightweight material. In our case we assume that the gondola is made from HDP high density polyethylene which has got a material density of 20 kg per cubic meter like a thermocall piece. So basically if you take material of length 0.26 meter, width 0.25 meters and thickness 5 centimeter that block of that particular sheet can be cut into pieces and joined together to create the gondola. So with this you can calculate the gondola weight in grams 20 kg per cubic meter will become 20,000 grams per cubic meter. So with that can you estimate the gondola weight? It is just 65 grams so it is a very very lightweight gondola. We have to attach the motors on the gondola as discussed now let us come to fin sizing. So for fin sizing as I mentioned we use standard parameters which are available in literature based on a survey of existing airships. So let us estimate the fin area the envelope area is known to us and there is a area ratio of 0.0594. Therefore the area of the fins total that is S fin comma t is going to be by this expression. Can you estimate the value please? The number is 0.4607 square meters. Then you can calculate the value of b which is the span semi span. For that we use the aspect ratio of the fins factor. So calculate the value please it is 0.2754. Then to calculate the root chord because we know the span to chord ratio from the table and we also know now the span you can get the root chord. Can you calculate the value 0.4896 meters. Then CT or the tip chord is nothing but root chord into taper ratio. Already you know root chord value so you can calculate this very quickly 0.4896 into 0.7083. The value is 0.3468 meters. So once you know the value you can calculate the value of each fin. Each fin will be obtained as a trapezoidal so a simple formula of trapezium where b will be the span and CT and CR will be the two edges. So this is the area of each fin 0.1152 square meters and if you make it 4 times you will get the weight of the total fin area. So fin mass estimation so total fin area is already known to us you multiply by fin material density. So for fin material we have assumed HDPE or some kind of a sheet of weight 250 grams of square meter plus you need to give some margin for velcro that you put on the bottom of the envelope and also ropes etc. So let us say 10% margin. So W fin is going to be 1.1 into 0.4607 into 250. Please calculate the value the value is 126.7 grams. Coming to the drag computation now drag estimation we have to use the formulae available in literature because one option is as I said you can do CFD analysis and get the value that takes time and effort and that is not very straightforward. We can look at literature and try to get some values of the drag coefficient. So bare hull drag can be estimated based on the Reynolds number for various kinds of airships and you have to multiply it by 2 because it is generally seen that drag of the whole airship is twice the drag of the envelope. So you can get now there is a confusion many people have between CD volume based and CD area based. So normalized with area will be D upon half rho V square A and normalized with volume will be D upon half rho V square V power 2 by 3. So be very careful. We looked at some data in open literature for small airships. There is an airship called Lotte which was the first solar powered airship developed in University of Stuttgart and we got some data regarding its drag coefficient. There is one number for bare hull and there are numbers for various deflections. So you can get the value from there. You can also use the Horner's formula which depends only on finest ratio that is the length upon diameter and also the Reynolds number. But the problem is this is completely independent of the envelope shape. So all shapes which have the same finest ratio and the same Reynolds number are going to have the same drag. So let us just check. So if you check this formula, if you check this formula against the Zeon data where L by D is 4 and Reynolds number is 7.3 million, you get the value of CDV as 0.029 whereas Horner's formula gives 0.025, which is a fairly close match, 13 percent error. So let us calculate the Reynolds number. So the length is 3.5 meters, velocity is 8 meter per second, viscosity 1.46. So therefore you can get Reynolds number as 8 into 3.5 divided by 1.46 into power minus 5. Calculate the value please. The value comes out to be 1.917 million. Remember whenever we mention about Reynolds number we normally speak in millions. So it is around 2 million. So we know the envelope L by D ratio. We also have the Reynolds number. So using the Horner's equation one can easily calculate the CDV value. So that number I would like you to calculate now. It is 0.03097. So now let us calculate the drag and thrust. We know that the envelope volume and the CDV values have been already calculated. Enveloped drag will be half into rho into velocity square into envelope volume power 2 by 3 into CDV because that is how we define the CDV. All numbers are known to us. So can you please insert the value and calculate? The answer is 1.5 Newton. Total drag will be twice because this is only for the envelope. So it will be around 3 Newton. That comes to 310 grams. So that means we need to put motors which can give thrust of at least 310 grams to be able to get 8 meter per second with this particular airship. Coming to the last part of the methodology, we look at the electrical motor selection and weight estimation. So thrust required is known to us 310 grams. We have this graph which has got a formula for motor weight. So from there you can estimate the motor weight. Please do the calculation and get the number. The answer is 38.6 grams approximately. Then number of cells required are available from that expression in terms of thrust required. Thrust required is 310.38 grams. So it comes to 2.31 which means it has to be more than 2 and less than 3. So you can go for 2 cells or 3 cells depending on what you think is appropriate for your airship. Then we go for current and propeller estimate diameters. Current has to be calculated and remember we have to increase by 20 percent. So this is the formula for current which requires you to put only inside the value of thrust required. So what is the value you get? 6.28 amperes. Put 20 percent more you get 7.52 amperes. So 7.52 amperes is the current rating of the motor and now we need to get propeller diameter. So again we use the same equation on the right hand side and you get the value. The value is 6.66 inches. Battery and ionic selection. So to estimate the capacity of the battery we start with the endurance of 15 minutes and the current is 7.52 amperes. So the capacity will be 2 into current into 100 into endurance. So that would be basically calculated and that is 3760 milliampere. So you require a battery of 3760 milliampere hours. So battery capacity is known. Should we go for 2 cell or 3 cell? Well let us check both of them. For 2 cell batteries there is a formula which has to be used. So please pause the video and calculate the battery mass for 2 cell battery. It is this grams. For 3 cell battery you have a similar formula. Please insert the values and calculate. It is 404 grams. So we prefer a 2 cell battery because it is coming very heavy. 404 grams is quite heavy for the battery. So we go with 2 cell battery. So now we need other equipment on the airship to be able to be remotely controlled. So there is a receiver which is around 30 grams. You need a battery which we have found at 2.66 grams. Then there are thrust motors and the lift motor. We assume them to be the same, 37, 38.7 grams. There is a yaw motor which is 19.3 grams. Then assume some wire weight. Then there are 3 speed controllers. Each of 15 grams can be assumed. So 45 grams. 3 propellers each of 10 grams. So add up all of this to get the mass of Avionics. It comes to 487.8 kg. So envelope is 579.7. Avionics is 487.7. Finns are 126.6 and Gondola is 65. So the total empty weight if you add up comes to 1259.11 grams. Now we estimate the CG. So what we do for that is for each component we will calculate the weight and the CG location and then do a product of these two to get the moment arm. So envelope is located at 1.6 meters from the nose, the CG of the envelope and the weight is 579.73. Therefore the moment arm will be the product of 579.73 and 16. Similarly for Avionics they are located slightly ahead because they will be on the Gondola. Calculate the value please. Just multiply 487.8 with 1.3 is 374.14 grams. Then Finns are having a large moment arm because they are located very far away. So their contribution is 354.7. Gondola is very small 55 grams located at 1.3. So it is only 84.5. The total weight is 1259.11 and the total moment arm is 2000.93. So CG will be this number divided by the total weight. So CG of the whole airship is going to be at 1.589 meters or 1.6 meters. So envelope CG is where the total aircraft CG is lying roughly. Now we check the payload requirement. So the empty weight is known now. Assuming that we have to carry 90 grams of ballast for controlling and for margin. If we use hydrogen, net lift 1602, excess lift will be calculated by net lift minus empty weight minus ballast. How much is that going to be? That is 252.89 grams. Therefore our requirement of 250 grams is met with a margin of 2.89 grams. It is a very small margin but nevertheless it meets our requirement. If we use helium on the other hand, the net lift is 1486 grams. The excess lift is nothing but net lift minus empty weight minus ballast. So you put the numbers there. What do you get? You get payload as 136.89 grams. So although this airship can carry some payload, it is not 250 grams. So requirement is not met. So what do we do? Either we shift to hydrogen with the same length 3.5 meters and you meet the requirement or you have to increase the length and then use helium. So this is the final parameters of the airship. The envelope shape is NPL, the length is 3.5, payload is 250 grams with 2.8 grams margin, metallized polymer of 65 GSM, volume 1.4 and the lifting gas hydrogen. Now let us see what happens if you change some of the parameters. For example, we have chosen the length to be 3.5 meters and we got a payload of around 2, with the excess of around 2.5 grams, 250 grams plus a margin of around 250 grams. That was for the length of 3.5 meters and for the gas to be hydrogen. If we use helium, we were getting negative payload or negative, I mean not 250 grams. Then what happens if you change the gas? What happens if you change the shape? What if the material of the envelope is changed? So all these things they can be checked if you make create a spreadsheet using the formula which I have shared with you. So here is an example of that spreadsheet. So in this spreadsheet you will notice that we are going for the baseline case. So the payload is 0.25 kg, velocity is 8 meter per second, endurance is 15 minutes or 0.25 hours. We are at sea level under ISA conditions. And the lifting gas is 1 which means it is hydrogen, envelope shape is NPL and the length is 3.5 meters. So this is what I have done in the tutorial. And if you do the calculations for it, you will see that we get a net payload of 252.51 grams which is 2.5 grams margin at an excess payload. If I change the gas from hydrogen to helium by putting helium here, you will notice that you will get payload of only 137.32 grams. So the excess payload is negative because we want 250 grams of payload. So similarly, if I make the length of the envelope, suppose I make it 4 meters and I keep the gas as helium, I will get not 250 but 459 grams therefore the excess payload is 2.09. So therefore what I can do is I can find out what should be the length so that I get excess payload equal to 0. So for that I will do what is called as a goal seek. So in goal seek, you go to what if analysis, you go to goal seek and you say that this cell L10 which is the value, I want to set this cell to 0 and I want to change the length of the airship. I want to change the airship length. So if I do that, it calculates and tells you that 3.5 is not enough but 3.71 meters length if you do then with helium also you will get the payload of 250 grams. So this is an example of using the power of excel and spreadsheet to calculate. Similarly, I can say suppose I now make the lifting gas back to hydrogen and if I make the lifting gases hydrogen then what happens? So you can see the difference. So if I make this as, so earlier I was getting an excess payload of exactly 2.5 grams, now I am getting 137 grams. I put this back to 3.5, I will be able to recover the numbers that I have earlier. Now let us go to change of shape.  So then what happens is you see if you take a GNVR shape you can get for the same length of 3.5 meters you can get payload of 719 grams that means your excess payload is 470 grams 469 grams. So GNVR shape is much better even though GNVR shape may have more self weight but its volume is much better. So like that you can do various kinds of what if scenarios to check. Let us see what happens if I change this lifting gas to helium. So with helium I will get slightly lower payload capacity compared to hydrogen but still I get 535 grams which is 285 is more than the double. So this way you can actually investigate various scenarios. Thanks a lot we will be open for any queries through our discussion forum where you can put your questions.


Hey there friends, how's it going? My name is Kevin and today I will be your 1-1-2 operator, or 9-1-1, 9-9-9, 1-5-6, whatever number you want to call, I'll be there, unfortunately. I'm the only one here to help you and I know that sounds terrifying. Imagine you're in mortal danger and your last line of defense is me. That's terrifying in itself. Ah, free game. Oh, I already paid for it. Ah, we'll miss. We'll check it out. Type city name. Kevin. They're like, I don't think you understand. Let's try Cork. Cork Ireland. Yes! I'm going to defend Cork. Rustallan Cork Bank. What? I don't even know these places. On Douglas, I know that place. I put my name is Help Me so that the calls can go a bit like this. Help me! Yep, that's me. Why can I not protect the city? Why will you only allow me to protect the surrounding areas? I want to be protector of the city. There we go. Cove is included. Fun fact. Actually, not that fun, but that's where the Titanic glass left from. And if I was on the 112 line to assist, wouldn't have happened. This is your work inbox. Oh, I was hoping I'd have like emergency calls in my emails. I've tried that once. It didn't work. Wait, maybe I should send an email. Hold on. Can I send an email? Send email. I will send an email to the fire department. Why are all these people armed? We don't really have armed police here. Here, you can check the objectives currently assigned to you. My objective is fight drugs. I don't know if the war on drugs is a good place for me to start on my first day. Solve all incidents connected to drugs. Okay, well, welcome to the task force. Your first task is solve all incidents connected to drugs. If you can't do it on your first day, you're fired. One of the other call takers reported an incident. An incident? What have you got? A bribery attempt? Let's just ignore that. I'm looking for drugs. Speeding. Oh, that just sounds cool. Ignore. Drug dealer.  You can dispatch them to any place or an incident using the right mouse button. All right. I'm going to send you over here. You go get them, please. Thanks. A new emergency call has been redirected to you. Fine. I'm kind of busy. What do you want? This is like the Green Goblin trying to fool Spider-Man. This is definitely, definitely a trap and the call. You can tell by the voice, you know, it's like when he was trapped in the burning building. I, I've seen too many movies to know that was a scam. Person hit by falling branch. A branch. Do you mean log or like tree or just branch?  Speeding. Suspects are trying to run away. Well, if they're willing to speed, I probably won't catch them. I need to actually start stopping some crime at some point, choking on food. Okay. I'm pretty far away, but I'll try. Yep. Any hour now and I'll be there. Current time is 110, 115.  That person is 100% going to be dead. It's been 20 minutes of them choking now. 30 minutes of them choking now? All right. It's been over an hour of you choking. I am going to assume you are dead. I'm sending the ambulance back. They're almost there. New call. Hello. I was trying to get my cat down from a tree in my backyard and I fell on my back. Oh, the poor dude. My back hurts as well. I understand. Just stand up, dude.  Hello. Sir, are you there? Another call solved. Firefighter needed. Large technical job. I don't have any firefighters, but I do some police to get you out of that elevator. They're confused. Oh, wait. No, they're solving it. They're fixing the elevator. God, they're talented. Another trap to an elevator. Stand to sound a bit like the boy you cried wolf now.  Fire alarms activated. Doesn't necessarily mean there's a fire. We'll skip that. Ahoy, ahoy. What? Tell me more. I've been followed home. Who followed you? What? Why are you talking like that? They have you hostage right now. Is there anyone with you? No. Well, then I guess you're not be followed if there's no one there. Is this a joke? Why would I joke? Could you describe him, please? Yes. What? This is a prank, isn't it? Are you on drugs? Drugs? Why would I take drugs?  You know, it's my first day, and I'm supposed to stop all the drugs, so I'm coming for you. What if he breaks the window? What if he breaks through the window? You should hide. That's why you should hide. I'm just gonna forget about that. I feel like following up with that incident could actually get me in trouble. I don't think I handled that too well. You know what? Fine. Fine. I'm too curious. Oh, we arrested her. Yeah. Your fault. Not mine. Trying to blame me when I did everything right. Why is there lightning? Is God angry again? Twisted ankle.  We don't want to have the manpower for this. What do you mean? My reputation was too low. Even your objective is stop road hogs. My boss comes to me and it's just like, okay, I know we told you to eliminate all drug issues in the entire city on your first day, but maybe that was a bit too ambitious. So just stop road hogs. I ignored a lot of speeding and red light offenses. I just don't see them as a big issue. I solved all the drug dealer ones, which is what you asked me to do. All right. I'm ready. Throw anything at me. Fire alarm. We're on the way. The police are coming for some reason. Look, they're all we have close, so you'll just have to deal with it. It's better than nothing. I sent a fire truck for a person hit by a falling branch, and for a person trapped in an elevator, I sent an ambulance. Change prices. Weird acting person. That's me. How do they know exactly where I live? Don't come to my house. He doesn't want to ride his bike because of the weather. Hold on. I'm sending a police unit over to me. Oh God, I got a call. I haven't been picking up my phone. Sorry. I got an asylum. You again? Stop calling this number. All right. Fine. What happened? Well, kiddo, that's natural selection for you. Best to look. I think one just got attacked by one of the lady bugs or possibly struck by lightning. Either way, just go catch a bus. Lie on the ground. Okay. Yeah, lie on the ground. They were going to say hello, but they just said hell. They've perfectly described, but it's like to be on a phone call with me. Okay. Should turn the phone off. If you say so, mister. Yeah. Good luck, kiddo. Awaiting further on my way. Oh God, stop calling me. I'm busy. How are you, my friend? This is freaky, but good you. He is polite at least. I know that song. Oh, I know that song. It's beautiful. Oh God. Does he need help? I love this car. You're way better than the kids. I just probably killed. You know, I need someone. Oh, I thought we were just talking about my music. We like, well, I'm glad to help. I'm sending an ambulance and a police. In fact, I'm sending every unit in the city to you to give you some help. And you know how I'm going to do it through song. I just got straight to him. I've arranged a big musical number. Standing by. Case resolved. I did that good. We can't proceed because of the weather. It is possible. If those kids can be out in that storm, you can too. Come on. Keep moving. Operator. Oh, there's a stabbing. Oh, stabbing back. Wait, your reputation was too low. Minus 13. That was way better. Alright. Maybe I'm not cut out for this. Maybe I should start it a bit easier. Oh wait, hold on. Oh, I ignored a call about an unconscious girlfriend. I'm sorry. I was just having a bit of a sing song on the line with someone else. Children were lost. Okay, that's also a bit of an issue. Hold on, hold on. Let's just back out, okay? We'll quit this job and get another one somewhere else. I'm getting a job in London. Alright. I'm sure I can handle 8,787,000 people. I've proved it by failing with the, you know, 200,000 people or so. That was too small for me. I didn't, you know, reach for the sky because I was so above it already. I'm making a lot of excuses here, but can I please have a job? Oh, that's romantic. That's so nice. Oh, he's joking. Okay. Oh, hi. Hi. It's my first day. I'm ready to take out all the drugs in the city. And this is where you will sit. You can put your headphones on already.  Just immediately lose your job. Skip, skip, skip. I know how to do this. I literally just sat down. She was showing me how the console works and an emergency came up. I just disregarded it. I didn't even mean to do that. I just autopilot ignored someone. I'm sending them all to meet up somewhere. I think it would be nice like a team activity. Wait, I caught a criminal by accident. Well, I was lucky. They're all just gathering around. They're all in the parking lot. Just doing donuts. Drunk person in a pub. Oh, Jesus. That's an emergency. Alright. What are they doing in there? Then comes the Asian man. Hello. Oh, hi. My friend wants me to drive drunk. They sound cool. He said he's a designated driver. So he's definitely sober. What? What kind of logic is that? Where is this call coming from?  Oh. Yeah, it is. We're going to kill him. Hurry before he hurts someone. Wait, hold on. I don't know where you actually are.  Oh, wait. It's here. It's here. Hold on. I'm heading out. This is way easier. They just gave me like one little borrow. Hello? Hello? And all these prank calls. Sir, are you aware that calling 112 unnecessarily is a serious crime? I am just not taking him seriously. I don't believe you. I don't believe you. I think there's no bomb. I really am playing with fire here. I'm arresting the person. That'll show him. Never prank call me. I hate that. Well, there's a knife in my thigh and there's blood soaking from it. Feels bad. Did he just feel bad manned me on the phone? There's a lot of communications going to evolve too when our generation are the old ones. Feels bad manned on PNG. At the other end, it's like, Pong! That sends out the police. You should take it out as fast as possible. No, you shouldn't do that at all. You'll bleed out. Just do it, I guess. I don't know. We'll learn that together. Well, it's your fault if I die. Yep. I kind of accepted that. Stop the floor. Use the belt. Lie down. Just take a little nap. I don't think that's the right answer. I already am lying. Don't lie about such a serious situation. How many thieves are there? I've seen three. Oh God, I'm sending so much police out to stop them. Can you scare them? Perhaps jump out at them with a mask and a chainsaw. Do you have an intercom in there? Yeah. Try to pretend that you're a police officer and tell them that the building is surrounded. Just role play, dude. You'll confuse them. It'll be so funny. Wait, I'm calling off the police because I think you can actually handle this. That's very good. Now what? I'm not sending any police. Receiving. Going back to base. Well, you still got space in the ambulance for another. The other person's having a heart attack, but they can wait. It's like ordering an Uber and going with the carpool option, but it's with an ambulance. I have nothing to do. I have officially cleaned up the city. Oh, amazing.  And that's it. I got a promotion. I deserve that. Can I afford another unit? I don't really want another unit. I'd rather keep the money for myself. All right, guys. I know this is a weird request from your commanding officer, but I want you to spell my name. Just get it to spell Kevin with the lines. Hi. There's a car following me. Could you please help me? I mean, What car is following you? It's a black sedan. Um, the thing is, I actually know the driver. You should lead with that. Who is the driver? There was a guy at a party and he was really clingy and I couldn't really get rid of him. So that's why I left. Try to lose him. You should try to lose him. Let's go with that, even though I have police just around the corner. Drive fast and chaotically. Are you sure that's the best idea? I don't think that's safe. I think it's a good idea because if you drive chaotically, the police will stop you and then you can get their help. Oh my God, look at him. He's speeding up. Jesus Christ! Can I get an ambulance out of there, please? Hello, I got a warning. I'm on a bad streak here. What's up? A woman was hit by a car. I might have caused that. At a road near... Ah, near... That's right across from... Do you know how to perform chest compression, sir? I'll tell you what to do. Please, follow my instructions. I don't know. I took a first aid course before, but it was a few years ago. I can't really remember. Okay. What now? Oh, no, you're actually making me choose push soft, push hard. Just second push. I don't know. Oh, wait. No, that's if you're in childbirth. Hold on. I got you confused with my other call. Right. The police are here at least. The ambulance is almost here. There you go. Did we save her? That'd be so cool if we saved her. Why are you resting somewhere? Oh, yeah. The driver who hit her, of course. I forgot. Funny, when I got hit by a car, they just went like, oh, Jesus. Are you all right to the guy who hit me? That was weird. He seemed as a ghastly, but how do you know? Then get him to sort the issue. Sending firefighters now. Thanks. I'm coming up. What? But make sure to take a lighter in case the lights go out and you need something to light the way. Sir? Oh, no. I think I just got a building exploded. I'm going to move on to my next call. Hello, caller. You're on to call me, Kevin. How can I help you? A block of flats is on fire. Oh, yeah. That was me, funny enough. I was just talking to the last guy. Oh, what a coincidence. It really is a small world. The fire just shot out of the windows. God, that's... That's mad. I hope the people got out and no one went back in. That would be... That would be dumb. I don't want to talk about it. Goodbye. Operator? They keep saying operator and it's reminding me a song but I can't play it. Where's that guy who loves music again? Good morning to you, sir.  I'd like to, uh... Confess? She's strangled. She's strangled? I strangled her. I knew it. I knew he was confessing. I'm getting so good at my job. Sir, where are you?  What? She's deceiving me. I'm so sorry. I'm sorry. What? Excuse me? She's up.  I'm so sorry. You got pranked. You're going to be in a YouTube video. You're going to be embarrassed. Parking violation. Can we get some armed units out there immediately? Roger. How much money do I have? I have 76,000. I would like to buy something, please. Give me a police patrol? No. Amba-bomb. B-bomb-bomb-bomb-bombalance. I think I need an ambulance. When you create a new unit, you have to... There. I'm starting. I just refused to listen. Operator? What is the song? It's like an old-timey song. I don't know. I can't remember it. I'm going to take out my anger on the people who need help. Hello? Hi! What would you like? I need... The code, dear. What do you need the code for? The... The pin code, huh? For your phone, is it? Try one, two, three, four. It's actually a good suggestion. I've worked with old people. It went technology, okay? It's not working. We need this line for people in real emergencies. Yeah, we're the problem. We are the problem, yeah. Someone probably died while I was making that call. I'm the only person in the city manning this line. I want to send the police out to that old lady. Shoot on sight, man. Another creepy caller. What? Are you in my basement, young man? A wooden stick? Is he a vampire? Is this Tommy Wiseau? Do the CPR. Sending help. Do the CPR until the help arrives. That's so cultural. Hello. Oh, no. It's a Karen.  They robbed and tried to poison me. Oh, my God. It's an actual Karen in the wild. What's the soup that bad? It's soup. Okay, should I send an ambulance then? Don't think it'll... Yeah, the police are definitely going to be there, too, lady. Don't worry about that. She's sitting there all smug like, now you're going to get it. Your manager's going to be shot. Oh, my God. Look at Karen. I want to see how that plays out, but yes, what's up? Are you on a train? Just get off the tracks. It's not that hard. You're like those people in the movies that just run straight to avoid something when a simple sidestep would avoid the issue entirely. I'm turning the engine on. I'll push the car. Yeah, push the car off. I'm trying to guide you to the solution so you can do it yourself rather than me telling you. Try turning the engine on. Wait and try. I know it sounds scary, but it might help. Wait 10, 20 seconds and try again. Remember to turn the headlights and the radio off. Why are you not just standing off the railway line? Oh, it actually worked. Move the car from the rail to break the barrier. Eh, let me have a think about this. I don't want to act too rash or anything. Um... I was just about to make my decision. I can't believe people are hanging up on me. That is so rude. Was Karen arrested? I believe she was. Fantastic news. I can't believe they literally called her Karen. That is excellent. As you get promoted, new districts will be added to the region of your... No, no, no, no, no. Why would you promote me and give me more districts? This is a terrible idea. And you didn't really ease me into it, like I have my old district, and then you gave me three more? Um, hello. I do have an emergency. It doesn't sound very urgent. What is it? Well, I know. That's why you're calling this number, right? Oh, sassy. Exactly. What is it? Do you have stage fright? What happened, sir? Uh, to then.  That's it. He's doing bad. Me and my partner, we, uh, played with a light bulb. I'm actually right! I'm just gonna be like, for pleasure. Oh, my God. Yes, there it is. It's stuck. I need help. Well, there may have been a light bulb involved, but there wasn't a very good idea. Eat spicy food and wait. What? I can't wait that long. What if it breaks? I need help. It's not that serious. It's just a light bulb. Uh, okay. You say so. That doesn't really make any sense for me. I didn't help that man. Alright, you know what? Maybe send an ambulance. There's a man eating spicy food, and he's really gonna need you soon. What's your emergency? We're stuck in an elevator. Help. Okay, what floor are you on? I'm not on any floor. I'm stuck in the elevator. Alright, stop being sassy. I won't help you at all. Calm down, okay? How am I here? Look, I get it. You're stuck in an elevator, but I've got a guy on the south of the city with a light bulb stuck up his ass, so it's not that bad, is it? There has to be a number to some technician somewhere in the elevator. Please, call them. It's not an emergency. Are you for real? We're stuck here. Oh, she didn't like that. I'm sending the firefighters, okay? They're coming. Actually, I think I'm sending a tow truck by accident. Either way, any competent person can help you. Oh, missing child. Probably the one I told to lie down in the lightning storm earlier. Hello? Creepy callers. Loads from today. What would you like to report, sir? There it. You sound pretty guilty.  There's a hope. That's just his mouth. What are you trying to say? We're out of water. Case resolved. What? You said you were out of water and then you sorted the burning building. What did you do? Did you spit on it? Going there. I think I did it. Fight drugs. Objective failed. But other than that, I think I did it. I didn't solve the bright idea one. Oh, they made the joke before me and I didn't even realize it. Oh, my God. I forgot to check the emails. Oh, my boss is not happy. Oh, my God, there was a serial killer and everything that I didn't catch. I did not piece these together because I've not been checking my emails. I apologize. I'm new, a little bit overwhelmed. But you know what? I think I'll end my shift there. I give this game a one plus one out of two. Fantastic. I really, really enjoyed it actually. I'm surprised by how much I enjoyed this. I hope you did too. Let me know if you did. I'd appreciate your feedback. Thank you so much for watching. I appreciate it a lot and I hope to see you next time. Bye for now.


we're going to rewind a little bit when she didn't have a lot and you know her husband as a bed was struggling and they had this horse at that time in her life she did a lot she was the she would go out early and get water for the horse feed the horse bring it fodder she would walk it she would go and get um date seeds and they would they would at that time crush it and it was a very labor intensive life and um at one point she had to walk about two miles to do this process of crushing these date stones and then they would carry these massive things on their head so I again try to visualize this she's walking two miles exhausted she's been laboring all day just trying to make it survive and who comes and crosses her path none other than the beloved sallallahu alayhi wasallam and this is his sister-in-law so you know sometimes and this is again something that we should just really appreciate that is lost unfortunately today in the nonverbal communication that can sometimes be really powerful not everything always has to be said sometimes the states and the hearts are communicating so the prophet sallallahu alayhi said him sees his sister-in-law in this state without a single word he stops his camel and orders the camel to kneel and then he's he makes a sound or if something to that effect which was an indication to her like come on I got you sit sit on the camel I'm gonna take you the rest of the way he had this compassion for his sister-in-law seeing her in this state but subhanAllah and I want you to see what she does this is again emotional intelligence of a wife and a woman who is using her intellect to assess the situation there's all these men here the prophet systems here I could really use a ride right but my husband is jealous without words without any words what does she do she just stands there and the prophet sallallahu alayhi sallam again he knows the hearts no communication they just understood each other he understood that her shyness meant she wasn't going to get on and he just proceeded forward and she went home rushed home to tell her husband about this whole incident what happened because she wanted to be transparent we and we have to again apply this in the modern context a lot of things are happening in spaces private and marriages and lives all over the place and everybody's all about privacy now give me a break you're married transparency you should have you know access to to one another's you know whatever is is a public right but this idea that no I can do my own thing and I don't have to share so just let's learn from her she wanted to again show her husband that I honored you in your absence so she tells him what happened and his response is also really beautiful because it just gives us insight that they actually cared about one another and it wasn't this whole you know power game all the time like I want this and I want that they weren't about that they were about the hearts so he told her he said by Allah you're carrying the date stones and you being seen by the process that I'm on with that you know with that on your head in such a state is more shameful to me than you having taken a ride with him so he's letting her know like I'm pained that you were in this that I've put you in this situation I don't care about that but they were so considerate of one another's feelings so we have to think about that in the context of you know who are we are we you know again not sharing certain things with our spouses or are we taking these positions that are not really thoughtful about one another's feelings and this applies to the brothers too I hope they're watching this it's or will watch it at some point but you know if your wife asks you not to socialize with certain people it's respect that you honor that request and vice versa and I think we just have to you know take take that you know Nessia from this but she prioritized her husband's feelings in that incident


Zero Accounting Software 2023 Enter Transaction for the Purchase of Inventory Using Bank Feeds Overview Get ready to become an Accountant Hero with Zero 2023 First, a word from our sponsor Well, actually these are just items that we picked from the YouTube Shopping Affiliate Program But that's actually good for you Because these aren't things that were just given to us from some large corporation Which we don't even use in exchange for us selling them to you These are things that we actually researched, purchased, and used ourselves Focusrite Scarlett Solo 3rd Gen USB Interface with Software Suite I've been using a Focusrite for years for my audio needs Before which time I had a USB microphone which plugged directly into the computer But I think you'll find, as I have found, if you want to increase the quality of your microphone You will need an interface and the Focusrite is the go-to interface As far as I'm concerned, I've been using this for years now It works well, it's easy to use, it seems quite durably built Because I only do the screen recordings, I only need the one solo interface However, if you have multiple microphones you need to plug in Or if you have other instruments you need to plug in You can look at a similar model that has more input ports If you would like a commercial-free experience Consider subscribing to our website at accountinginstruction.com Or accountinginstruction.thinkific.com Where we have many different courses you can purchase one at a time Or have a subscription model giving you access to all the courses Courses which are well-organized have other resources like Excel files And PDF files to download and no commercials Here we are in our Custom Zero homepage Going into the company file we set up in a prior presentation The bank feed file We're going to be duplicating some tabs to put reports in Like we do every time, right-clicking on the tab up top So we can duplicate it And then we're going to right-click on the tab up top again And duplicate it again Back to the tab to the middle Accounting drop-down We want to open up the major financial statement report of the balance sheet And then we'll tab to the right as the balance sheet is thinking Accounting drop-down This time the income statement The other financial statement report Let's go back to the balance sheet The date looks good for us Because the data I am uploading will be in 2022 For the income statement I'm going to bring it back to 2022 Because that's the date of my data input So January to December Let's just say of 2022 And update So this is what we have thus far Let's go back to the first tab now I'm going to go into the bank feeds We've uploaded the bank feeds in a prior presentation Therefore, if we go to the accounting drop-down in our bank accounts We've got the bank information here Drop-down on the manage of the account I'm going to the account transactions That'll take us to the detail of the bank feeds We are focused on the reconciliation process And we are primarily building our financial statements Directly from the bank feeds Therefore, we have the information from the bank on the left And we're in essence creating the transactions on the right as we go Now we want to think about inventory Inventory often being kind of a wrench in the system One of those things that kind of stop the cogs from moving Sometimes when we are trying to build a system That is just constructed from the bank feeds To think about that and how we can deal with it Let's take a look at our flow chart This is a QuickBooks desktop flow chart From the home page of the QuickBooks desktop But we're just looking at it as a flow chart Because the accounting flow will be the same Basically for every kind of accounting system in general So we're looking at inventory now And thinking why is inventory kind of a problem And then how can we basically deal with the inventory Now there's two The inventory actually goes through two different cycles Because of course we purchased the inventory Which means it's part of the vendor cycle In other words cash is going out At the end of the vendor cycle for the purchase of good services Our assets inventory And then of course we're going to sell the inventory And that's going to be part of our revenue or income cycle We're at the end of the day We expect money to be coming into our account For the sale of goods and services In this case goods So obviously what happens from the banking side of things What's going to happen on the bank statement Is when we buy the inventory We're going to see a decrease to the checking account And when we sell the inventory We're going to see the increase to the account For the sales price of the inventory The problem happens when we're trying to track the inventory As an asset As opposed to just simply expensing it When we purchase the inventory So let's think about the easiest ways to deal with inventory To the more complex ways to deal with inventory Because the easiest way we could deal with inventory Is we could try to stay in a cash based system Right, there's problems with that But that's the easiest thing we could do If we can't stay in a cash based system Then we might use some kind of periodic inventory system Tracking inventory outside of the zero accounting system In an Excel sheet or something like that And making periodic adjustments And or we can actually track the inventory On a perpetual inventory system within zero Which is typically the most complex type of inventory system Alright, so the easiest kind of inventory system We try to just keep on a cash based system So note that that would only work If you're only holding onto minimum inventory So if you're in a system where you're like Doing custom projects or something like that And someone wants something You say, I'm going to buy the goods that I need The inventory I need and make any adjustments to them And then sell it right away Then you have inventory But you're turning the inventory over You're selling it so quickly That you're not holding onto it And you might be able to get away in some circumstances With simply a cash based system Make sure to run this by your CPA firm Or something like that It's your tax professional And make sure you're in compliance With whatever you need to do For whatever reporting purposes you need Such as taxes or external reporting purposes But that would be obviously the easiest thing to do So that means that If you were trying to stay in a cash based system With the bank feeds on the purchase side You can wait till something clears the bank And you'll pay for it And then when you record it as a decrease To the checking account The other side will just go to cost of goods sold expense Noting that you will be recording cost of goods sold Before you actually sell something But then shortly after that time You will make the sale After you've done whatever you need to do To then make the inventory sellable You're going to sell it And at that time You could wait till the deposit clears the bank If you actually made a sale to someone They paid you And you're trying to say on a bank feed Generated reports You can wait till it clears the bank And record in essence the deposit as revenue In that case then You wouldn't have to deal with on the sale side The reduction of the inventory That cost of goods sold And tracking the asset of inventory Alright, but If your inventory is significant at all In dollar amount Then you don't really want to do that Because what you want to be able to do Is track the inventory that you're holding on to As an asset In a similar fashion as we talked about With the equipment And then when you sell the inventory You want to decrease the inventory And record the related expense Cost of goods sold When you sell the inventory And that way You're matching the expense The inventory that you purchased On the income statement In the same time period that it was consumed It was used lowering inventory You sold the inventory in order to record Or generate sales So that's the general idea Now you could do that two ways You could use the full-service perpetual inventory system Within zero But that takes a lot more work to set up And it puts a bigger kind of problem point Into dealing with the bank fees to some degree So you could do that Or You could try to track your inventory externally On something like an Excel worksheet For example And then you might make periodic adjustments to zero On a daily, weekly, or monthly basis So in that case, for example On the vendor side You might purchase the inventory And then whenever you purchase the inventory Instead of recording it As it goes to the bank feeds Instead of recording it as Cost of goods sold You record it as inventory the asset However You're not tracking the inventory Within the zero accounting system In other words You didn't put an inventory item in place You're not generating any reports within zero That track the units of inventory You're only dealing with a dollar amounts of inventory As you purchase the inventory You will have to track the units of inventory On a separate sheet So when you buy five units of inventory You will track them on Excel Or something like that Or if you're using a Shopify platform Or something like that You might be tracking them in Shopify Or something like in units And then you're typically going to want to do some kind of Flow assumption So I won't get into that in detail Because that's a whole course in and of itself But you're talking first and first out Last or weighted average Usually those are the two main ones Or last and first out But those are the two main ones The first two And then what you'll do is You'll count your inventory periodically At the end of the day At the end of the week At the end of the month See how much you sold Meaning you take your beginning inventory Minus your ending inventory And as in beginning plus purchases Minus ending Will give you your cost of goods sold And then you can make adjustments To the dollar amount in the zero system Periodically So that you tie out to what you have On your external sheets So then you just decrease the inventory Record the cost of goods sold On a periodic basis When you actually sell the inventory Again, you can kind of stay in a cash based system If you wanted to Meaning you could wait till the deposits Clear the bank And still record the deposits As just revenue And that way What you're not doing Is you're not recording the cost of goods sold At the point in time That you record the revenue But instead Doing adjusting entries At the end of the day, week, or month In accordance with your External periodic depreciation schedules In Excel or something like that So that's method number two Method number three As a full service inventory tracking system Within zero So that you're not only tracking the dollar amount Of inventory on the balance sheet And the cost of goods sold on the income statement But also making a separate schedule Which also tracks the units of inventory That you are purchasing Now remember that if you're dealing with inventory Zero has a pretty nice inventory tracking system But it's not the most advanced inventory tracking system So especially if you're using Something like a Shopify or Amazon That kind of business Then you might not want to track inventory On a perpetual system Within zero because you might be tracking it Using these other platforms So you want to think a lot On what your inventory tracking system is going to be And then how you're going to utilize zero within it But if you track inventory within zero That means that when you purchase the inventory Now you have to not only record the account But also the item of inventory Which adds a level of complication Because you need to set up your inventory items And apply whether they're going to be taxable or not And then have an item That you're going to be tracking When you record the inventory So that when you buy the inventory It's going to increase the inventory account And create a sub ledger tracking by inventory And then when you sell the inventory You have another level of complication So it's going to be a lot more difficult to wait Till something kind of clears the bank And then just try to record revenue As it clears the bank Because you're going to have to track the actual thing That was sold The unit of inventory that was sold Using the items So the items become important Because the items are going to be the things That are going to allow you to track the units of inventory So that's the general idea So let's just take a look at an example here If I go back over I'm in my bank feeds again So I'm in the bank feeds I'm just going to look for a transaction on 817 That we can mess with here This is a Primerica transaction 817 Okay, so let's imagine we're just going to use the easy method first And then we'll take a look at some more The other two methods later The more complex methods So let's say that we have Primerica 01 So I'm going to copy the vendor I'm going to put that here Primerica 01 And I count I'm going to have to add the details So let's go ahead and add the details here And so Primerica reference And so notice you do have the capacity to add an item So if you were dealing with inventory items Then you have your capacity to deal with the items Which might help you to implement the tracking of the inventory As you use your bank feeds But it's still going to add some complications We'll talk about that later Here we're going to not track the item We're not tracking the inventory on a perpetual system In other words, at this time We're not going to be recording it to inventory the asset But instead we're going to imagine We're just going to expense it to cost of goods sold So here's our cost of goods sold account And so there it is Now if I record this transaction We're going to have a decrease in inventory The other side goes to cost of goods sold Now what's the problem with that? The cost of goods sold is being expensed Even though it's not tying to the related income yet That's why we usually put it on the books as an asset And then expense it when we use the asset And record the cost of goods sold related to the inventory The revenue that was generated from the sale of the asset However, if I don't have a lot of inventory on hand And I'm going to turn around and sell this item I'm going to mark it up to whatever $100 and then sell it Really quickly I don't have a lot of turnover There's a high turnover I don't have a lot of inventory I'm holding on to Then you might be able to get away with in essence a cashed based system That we're talking about here Now if you were going to do this all the time And this was your major vendor that you bought inventory from This is your standard method You could create a rule for this just like we did in the past You could go up and say I'm going to make a rule for it And then make this your standard rule That you're just going to expense these purchases to cost to goods sold And then when you make the sale You're just going to record You could wait till it clears the bank feeds as revenue And record the sale or the deposit to revenue And that way when you make the sale You don't have to deal with cost to goods sold Because you already expensed it When you purchased the inventory Now again, that will be a problem You can't do that If you have a substantial amount of inventory you're holding on to For example And so that would only be applicable or possible in certain circumstances Alright, so let's go ahead And I'm going to go ahead and record it So let's save the transaction That will record it And then I can match the transaction So now we have the matching there This will reconcile it So now if I go to the balance sheet We have recorded it So if I update the balance sheet And I go into my liability of the checking account Because it's at a negative balance at this time Which is quite disturbing But that's okay Because we just haven't entered the beginning balance yet Our business just isn't rolling yet Any second now The business is going to start making millions Alright, so in any case This is going down There it is right there It's a spend money form Just like normal If I go back to the balance sheet We didn't record the other side as inventory It's on the income statement Updating the income statement And we just expensed it as cost of goods sold Again, that looks funny right now Because there's no income related to it Because normally we wouldn't have costs to goods sold Unless there was income So the next thing that would happen Is we would make the sale And that might come through with a deposit form And that would match out To the cost of goods sold Alright, just to If I go back to the first tab Just note that we have If I look at the Account transactions We've been building our account transactions Which are now reconciled in here So we've been making these transactions As we go and tying them out to the bank Which is a part of our bank reconciliation process Our bank statement items have already been there And we're just ticking them off As having been reconciled As we create the transactions Then if I go to the contacts And look at our contact drop down We can see that we have also been constructing Our contacts as we go And if I go to the accounting drop down And take a look at our chart of accounts We have been constructing Our chart of accounts has been growing As we've been doing our data input In basically a customized type of format Alright, let's open the trial balance Just to see where we stay and tab Into the right, right clicking Duplicate And we'll go to the accounting drop down Dropping down to the accounting That's the wrong thing I want to go into the reports Dropping in, man Dropping into the half pipe This is a trial balance Trial balance And you got to You can't have any fear when you're dropping in You got to just You're just dropping into the accounting I don't know what I'm talking about This is where this is the balance sheet On top of the income statement So we've been doing our checking account The equipment cost to good sold utilities And the telephone as of this point in time