So I've been running Linux on my desktop since around 2010, making about nine, you know, nine almost 10 years of full-time Linux usage. Now one of the things that a lot of people do is they talk about switching to Linux and then they go, but I can't run this or I can't run that. And gaming is one thing that I know some of the games and this is one of the reasons I do have a Windows computer dedicated to gaming at home. Mostly my kids use it occasionally. I play a couple of games on there, but the valid reason they're coming light years ahead. They've gotten way better, but not every game works on Linux yet. So this is more about the creative workflow. And Chris from Cross Talk Solutions says, Tom has definitely said great things about Papo S and he is doing some investigating Linux, but he's got the Adobe suite of products for my workflow so I can't switch for my own system. And this is not something I'm picking on Chris at all about because I want to point out something about statements like that because they're very valid. Workflow is a huge problem. You take the time to learn, you get really good at a workflow, especially when in the case of me and Chris, both, we have businesses to run. We are not YouTubers full-time, that isn't where our life is, and even then changing your workflow once you've created a workflow to make your living is difficult. When you do it as a side, you have to decide how much time to want to dedicate to learning something new. So I do realize those challenges, but I chose to not use the Adobe suite of products for my workflow. I know there's a couple of times I've had conversations, I remember Chris when he was talking about crashing problems with Adobe and there's been a few people talked about some of the updates with it and dealing with Windows updates that they kind of wished they would have taken the time to run Linux, but I have taken the time and I've put the time into it. So if I were to switch to Adobe, it'd be hard for me, so the opposite can be true as well. But I don't know the reason to switch to Adobe, or, and someone's going to bring it up here, DaVinci, because I'm aware of DaVinci. I know it exists, but I'm going to use the same excuse of I don't feel like changing my workflow because it really wouldn't add a lot to my day. So we're going to talk about the tools I use real quick right here in 2019. So I am using PopOS, and the thumbnails that you see were created with GIMP. Now I come from a photography background. I was a long time, intense Photoshop user, got quite good at it, but I decided to put my nose to the gradients going, which means I just watched a whole lot of YouTube videos and learned how different functions work in GIMP. There's some great tutorials out there. I can't name each person because it's not like I watched one channel, but if you search, you'll figure them out pretty quickly because there's going to be always new people out there. You can do the majority of the Photoshop functions, but no matter what, I got to admit GIMP seems to have a few extra steps or things that you didn't have in Photoshop. So Photoshop is nicer than GIMP, but for a workflow, GIMP works great, being able to create these thumbnails, being able to create transparencies and stuff like that. And I want to break down a myth real quick here about something that, well, maybe a myth. I've seen people say it doesn't work that way, but it does. So here's a quick Google image search for Linux. And what I'm doing here, I'm going to change it to transparent. And the reason I'm doing it, let's find a transparent tux. There we go. Whoops. I only want the image, open image, new tab, copy image, paste it as a new layer. I'll resize it real quick. Whoops, wrong tool. But you can see I can grab an image off the internet, off the web, copy, paste, the clipboard works fine. So still not Adobe, but those functions that you can do in Windows where you can grab things and not have to save the file, add the file, go through that. You can quickly produce things and edit here. And then it's layers based, so if I want it on the top layer, so it goes over this, I can just do that. And now we've added a ping window to this. So it's not like this myth that there's constant command lines or that copy and paste doesn't work the same. No, actually it does. It works much the same. You can handle copy, paste and easily edit and change things and move things around. I grab this logo off their website and just paste it in here and away we go. So we're going to discard those changes real quick. And then Kaden Live for all the video editing. So video editing has come a long way. Kaden Live, if you've tried it before and you go, didn't it crash all the time? It sure did. Every edit almost came with every minor change was Ctrl-S, Ctrl-S to keep saving. Because, yeah, it seemed to crash quite a bit. They have come a long, long ways. I've donated to this project many times. So it is how I edit all my videos. The only thing, and if anyone's ever wondering how I do these titles where it says large systems, third party renders, the titling sucks in Kaden Live to this day is not wonderful. You can do PNGs and transparencies, but I do them all separately in different things. The titling is the one thing I really wish was better. This is the title editor in Kaden Live. And so yeah, I'm always looking if someone has a great title editing that's open source besides Blender. Yes, I know you can create all kinds of awesome 3D animations in Blender, but boy, Blender is really difficult to use. So I don't have time to learn that. But so Kaden Live for my video editing still works great. And this is, you know, my go-to for the video editing. Now video acquisition is right here, OBS Studio. I think Chris even uses this. OBS is actually cross-platform, runs great on Windows and Linux. I love the inception view that you get when it does it like this. But this is where I'm recording right now. So this is how I acquire these videos when I'm doing screen captures. And then for everything else, flip to the other screens. I'm just right here inside of the, you know, File Manager, Nome File Manager. This is PopOS, so it's the PopOS File Manager. And this is a card reader to pull cards out of the camera and you can just drag and drop videos in. Yeah, it's not a removal, it just warned me it's not a removable device. Generally speaking, I don't edit right off the card. That's why I didn't see that error. I had to take a second to read it.  I usually, and these are Windows mounts, if you want to say that, it's a Samba mount to be technically correct. But in Nome, in the Nome File Manager and the one that comes with PopOS here, you just type smb colon slash slash, and the, well I'm using IP, I know I could be using UNC names, but it's just the same as it does in Windows. I can mount and save things to these Windows shares, Samba shares on my FreeNAS, and my FreeNAS is connected at 10 gig between my computer and this, so it's no problem for me to edit across these. And what my general workflow is, you know, copy the card cameras, copy the cards, drop them into here, and you can see all these list of videos in here. Getting clients in 2019, hey, there's the video for it. And it's gonna import the clips and put it together. So pretty straightforward how all this works. You know, this is fairly easy. Drag and drop, pull things in, pull these videos in, and away you go. So it's not like I'm doing all this command line magic and it's really hard to do inside of Linux. It's come a long way, it's become quite easy to do. I just wanted to highlight that. If you take the time and you want to put the time into the changing workflow, you have to have the time and say I'm going to make the time to do it, but it can be done. And like I said, all these are absolutely available in the Papa West store. So let me pull up the pop shop. And you know, no magic to install these. I just type in Kayden Live. Hey look, it's installed. Then you type in GIMP and there's GIMP. And then I don't remember though if OBS, I think OBS you might have to load third party. Yeah, the Sony thing, oh no, OBS is, there we go, OBS was installed from here as well. I do take and change repositories for OBS so I can get a more up-to-date version on there. That's the only thing I did do differently as far as that, but once again, not hard to do. They have a download on their website so you can do that. But like I said, hopefully this is gonna get you an idea.  You just have to learn something new. No, you have to learn something new and you have to decide if those features in Adobe Premiere are ones you really use. Now I've produced over 700 videos and uploaded them to my YouTube channel here as of April of 2019. And so I can tell you that they work. I can tell you that this workflow works for me and it's made the channel what it is today. So I'm really happy with it. I don't really have any plans on changing because like I said, I'm really, matter of fact, this version I'm testing right here is a slightly newer version. If you notice how it may look a little bit different if you're running Kaden Live, they just released this on Thursday. It's a new refactored code version I'm testing out. So it's so far hasn't crashed. So that's good. The other one's pretty stable. The standard one that you just load out of Papa West has been quite stable for me and works very well. So these are tools you can use. They are out there if you wanna take the time to learn them. All right, thanks. Thanks for watching. If you liked this video, give it a thumbs up. If you wanna subscribe to this channel to see more content, hit that subscribe button and the bell icon and maybe YouTube will send you a notice when we post. If you wanna hire us for a project that you've seen or discussed in this video, head over to laurancesystems.com where we offer both business IT services and consulting services and are excited to help you with whatever project you wanna throw at us. Also, if you wanna carry on the discussion further, head over to forums.laurancesystems.com where we can keep the conversation going. And if you wanna help the channel out in other ways, we offer affiliate links below which offer discounts for you and a small cut for us that does help fund this channel. And once again, thanks again for watching this video and see you next time.


So people, I am back with another outrider's video and today guys I bring you what's possibly the fastest Legendary farm method in this game now. We've got the original captain We've got the five chest farm which I have featured both on my channel by the way Oh, there's a chess M as a grab that while I'm here But yeah, we have the original captain farm We have the five chest farm, but this actual other captain is much much quicker If you do enjoy the video leaving a like really helps out and if you like what you see I want to see more outriders on a Daily basis from the demo leading up to the full game and daily streams Make sure you subscribe and turn notifications on now credit for this find goes to British legacy I'll link his channel down below in the video description He comes to my stream and showcases to me and it is just way faster. It's another captain You can literally just run in kill him instantly die Vince repeat so fast. So here we go. This is the actual farm I'll show you guys exactly. Oh, I've got that one. I'm here too ba-bam There we go. Yeah, you just run in here and he's literally right here There's no other ads to fight. He literally is there. Bam.   It's just so fast And like I said, it's literally just that when they're spawned there run here Just kidding Now there's a guy who's been doing this. He did it within about five hours. He had seven legendaries This is like the third or fourth time I've killed him. I can tell you straight away This is definitely faster. They're definitely faster than the other captain farm It really is this simple again if you die here So I just showcase it one more time and I'll show you how to actually restart this mission how you can get here So if you do mess up and yet so then it is progress Had to come back and rinse and repeat this mission is pretty simple So killing one more time and then we're going out. I'm gonna go with my shotgun this time See what we can do so fast. We can actually keep him with a shotgun people Let's pop my Super Saiyan rounds chop him big why not? Oh? Oh Oh Bear bear bear. I love my shotgun. I love my shotgun Got a blue there may as well disassemble that. There we go.  So you gotta go to return to lobby So turn to that lobby and you want to select obviously want to be doing this on a world tier 5 or so So complete the game first obviously will complete the demo first other list of people then you can come back and select Story points or world tier 5 select story point and you want to pick at this one here Meet with Jacob and Shira at her command room. So you select that confirm for to confirm Continue game and there's a little bit of flying through ads you have to do before you get to that captain But once you act the captain you can rinse repeat farming him really really easily So yeah, this for me is Definitely faster than the original captain. I don't know whether it's better in terms of actual loot I mean me I've done the original captain. I mean I found that original captain and for two days straight Didn't get nothing quick to do the five chest farm got two legendary is there This captain gonna farm later today see how it goes But what I've been told from people that have been doing this is unreal You can skip that cinematic as well. You don't need to watch that. So once you've done that you then just go into the mission And we run for the entire thing people just so you know exactly what you got to do and where you got to go Well, yeah from what I've seen on this it's way way way quicker than the original captain I can probably kill this guy twice three times her one run of the original. So yeah Definitely worth trying out at least like I said from people who in my stream. They've said this is just the best by far Yes, skip them cinematics. We don't need to watch them cinematics at all So yes, if you are interested in the outriders and live streams that is me all over people I mean streaming literally every day since the demo come out I'm gonna do so all the way up until the release of the game and when a game comes out That's when shit starts people. Okay, so just follow the mission. Like I said, there's a few ads you have to take out So we'll do that Well, I could say once you're actually here once you're at the captain the farm starts kill him die to the edge Respawn outside the room rinse repeat until you get a lot of loot people So these you have to take out these ads I don't think you can progress without killing them. So we're just gonna take them out I'm gonna get lucky here people recording live for this video my gal is no drop imagine that in him scream for sure Well, this shotgun. I'm using with the first one of that the second The second one I got was a Rayrugs gays is it gays or glazes this one here on my back I'm talking about it's a bit of a beast to be honest But I'm a shotgun not gonna lie. I'm a shotgun all day every day There was a few as you don't like I said, but if you had to kill all these to get back to the captain every single time It wouldn't be worth it, but just take these out once and you're good. So two more. All right, mate How are you doing? There's the last one. There's the last one bad app Make sure none these sneaky whites because these white sometimes look look like legendaries people there we go Okay, so you progress again. There's one more set of ads you do have to take out Nothing crazy No, I do a couple of chests along this run as well a couple of chests along this run Which can pick up to there's one round. He's a one-round here. Oh It's after this it's after this so we take our dads here and then we're good then it starts So we take these out. Oh, oh Boom, okay Come on. Whoa. Oh There's one chest there. We're going open it in a second Yeah Yeah, we ain't going nowhere.  You know, I'm gonna try my dual pistols out is um There's a legendary dual pistols as well, which I need in my life. They look so cool Come on. Where you going? Where you going boy?  And there's another chest on the inside of this door too, I believe So when you come here for the first time five minutes, these chests you can grab There's one right in front of me. I'm just gonna replaying my ammo Run over here and grab it.   There we go. So I'm right back outside the room pop that super same rounds Let's drill him up unless you miss like me because I'm a noob Boom All this guy's name is the vanguard captain. So just so you know, this is a vanguard captain farm There we go people you can rinse repeat this for as long as you like And there we have it guys there. We have it So use this see how it goes for you and let me know down below But it's definitely in my opinion the fastest method in the demo so far We have found in farming that loot and I hope you enjoyed the video guys If you did leave a like really helps out and hopefully I will see you on a stream on the next video


Thank you so much for being here, for listening. I'm going to be talking about REST APIs here, and specifically, security of REST APIs and kind of even more specifically, authorization, authentication within your REST API. So hopefully that's what you're all interested in. There's going to be a little bit of knowledge of Django REST framework that's going to be helpful, but hopefully if you haven't gotten a chance to play with it, I'll give you a very quick primer that hopefully will kind of get you started there. So what are we going to go through today? We're going to talk about why REST. Why is this important right now? Why are REST APIs a big deal? Why am I talking about them? And why have they changed a little bit in their scope and caused all of these, at least for me, security considerations? We're going to talk a little bit about what the state of REST is today.  And then we're going to get into security a little bit, quick overview of kind of the considerations around security, authorization, when you're doing a REST API. We're going to talk about some of the strategies that we've come up with to write clear, maintainable permission schemes for your API. And then we're going to talk a little bit about what I hope happens tomorrow. And I think our tooling is not quite there yet, and I want to talk about how we might be able to get it there so that we can write really clear, sane, easy API permissioning. All right, so let's get started. Why are we talking about REST? And the simple answer is all of these guys, Angular, Backbone, Ember, and so on, have just exploded in popularity in the last couple of years. And there's all this growth. They're really taking over a big chunk of what we do as web developers. And so the more nuanced answer there, then, is I want to talk a little bit about kind of the pieces of your app, what's running where and where these new JavaScript frameworks come into play, and how that changes the game a little bit. So you can break down your application into three basic components, very roughly. Display logic, which is happening traditionally on the browser. App logic, which is kind of what's running your app. And then data stores. And the traditional way that historically these have been broken out is the display logic happens on the front end or in the browser. Pretty straightforward. And then your application logic and the data stores and all that all lives on the server, the back end. And historically, we've used HTML, CSS, and JavaScript to talk to the browser. And then the browser posts some HTML form back to the server. And it all worked really well until we wanted to do more things in the browser. And we came up with this Ajax thing, and we sort of shoehorned it in there. And that worked fairly well for a while. And things grew and grew. And we started doing more and more of the application logic on the front end, in the browser. And this is really with Angular and Backbone and so on. That's where this really kind of came into its own, is huge portions of what your app logic, which traditionally lived on a server, is now happening in the browser. And it turned out that app logic needed to sit a little closer to your data. And so we came up with, or it had been around for a little while, but we started using REST really heavily to shuttle that information back and forth at a lower level between the front end and the back end because you're doing all of this app logic in the front end. So let's start talking about how we do that today, the state of REST today. This is just Google Trends, which is, you know, take it for what it is. But the blue line there is Django REST framework. The other two lines are Piston and TastyPie. I think there's a couple of interesting things to note about this graph. One is Django REST framework seems to be the clear winner of this crew at this point. And it's really only happened in the last couple of years. You know, I think there's a huge community around this now. And, you know, there's a lot of tooling around it, which is great. The other thing to note about this graph is just the magnitude in general, right? All three combined, it's really exploded in the last year or two. So this is, you know, to me, this says this stuff's pretty important and growing in importance. So I want to give you a real brief overview of what Django REST framework gives to you, just so you get the ecosystem a little bit. There's serializers, which help you translate your Django models, your data, into a representation to be sent down over the wire, so JSON, XML, that sort of thing, and to be reinflated on the way back. There's views, which kind of connect up the query set, so your data, with that serializer, and then you connect that to an endpoint. You can serve, in this case, cats at a given URL for your API. It comes with a bunch of authentication stuff.  They're, it's pluggable, so you can down, you know, you can pip install some other ones. But there's a really, you know, pretty straightforward framework for adding authentication into your API, and then permissioning. And we'll dive a little bit deeper into those, too, the rest of this talk. Cool, so let's talk about security, authorization, authentication, in the context of this REST API. So you remember this diagram, where the front end, the browser, was swallowing up your app logic. There's another important way to think about this, I think, which is a lot of your app logic is now running in this insecure browser environment, right? If you think about it, we've been able to rely on the server being, you know, presumably secure, right? That code there, you know you wrote it. You know what's running. The browser, not so much, right? The browser, anyone can do anything. A nefarious agent can, you know, mess with whatever they want. And as soon as we started doing more of the app logic in the browser, and getting closer to the data store, it opened up a lot of new security issues that I think that we, you know, we don't have a lot of practice working with as web developers working in Jango more, you know, historically the way Jango's worked. So there's new concepts to sort of wrap your head around here and some new security issues to be aware of. All right, so I want to go quick overview of the kinds of authentication. Just to give you a sense of, like, what's involved here, right? Why is this such a big problem? It's sort of an n squared n cubed problem because there's so much going on. Authentication, right? There's a lot of different ways to authenticate. Many of these are built in. Some of them you can, you can pip install. Like I mentioned, you've got HTTP basic auth, Jango session auth, token auth, OAuth, JSON web token auth. There's a lot of different mechanisms that you can install to do authentication. And the key here is probably most of these web apps are not using just one, right? So, you know, you might use Jango session auth as kind of your main authentication format. But then also if you're going to do a password reset, there's a token there and that's a different kind of authentication. And maybe you want users to sign up with Facebook and then that's another kind of authentication. And suddenly you've got all of these different levels of authentication that you have to deal with and cross-reference with all the different kinds of permissions that you care about, right? And there's a lot of these as well. So, you can have table level permissions, right? Can you access the cats or not? There's row level permissions, right? Is this your cat or is this someone else's cat? And what does that mean for your permissions? There's column level permissions. So, as much as we love cats, let's talk about, you know, the user model, right? You might want your users to be able to set their name, right? Change their name in your website. But you probably don't want them to be able to set the super user flag, right? And so suddenly you've got these column level permissions where you have to say, these kinds of users with these kinds of authentications should be able to touch these columns, not these columns. And then HTTP verb permissions, which roughly analogous to read, write, and that sort of thing, read, write, delete. You know, and so, you know, like I was saying, all of these things combine and you start to get this n squared or n cubed problem because there are other factors you need to take into account where there are a lot of different combinations, a lot of different situations that you need to account for. And it gets messy really, really quickly if you're not careful. So, let's talk a little bit about how we do a good job of this today, right? What tools do we have at our disposal today to, you know, put some order into this and make it maintainable, make it sane? So the first and really the biggest concept that I want you all to understand and take back and implement is small composable permissions. Take those permission classes in Django REST framework and make them as small and focused as possible. And you'll see later we're going to use, we're going to use a tool to kind of compose those into more complicated permissions. So, you might have some HTTP verb permissions, right? So we can create one called isPost, subclass the permission class, and then hasPermission, this function that says, you know, does this person have this permission, really just checks, is this a post? And that's it, right? On its own, pretty much useless probably, but when we start composing it with other things, you'll see the power of this. And then so you might have one for isPatch, you might have one for all the HTTP verbs, right, and then these become tools in your tool chest that you can apply to more complex permissioning problems. Let's look at user status. You might have an isAuthenticated permission, right? And this one that has permission just checks, are you authenticated? There you go, simple, easy to unit test, easy to think about, easy to reason about, and they'll come together in really powerful ways a little later. You might have one for isSuperUser that checks the SuperUser flag. And then, you know, all the other authentication methods, right? So you'd go on and on and on. So, you know, if you have Facebook authentication, you'd have some of these for Facebook. If you have that URL token as an authenticator, you'd have one of these for that, right? Just really simple checks. You're going to do the same thing potentially for ownership, right? Are you the owner of this cat? And there's a little bit of a caveat here, the way that Django REST framework is set up, it's really hard to do this check in the hasPermission like you would want, right? So for list level permissions, getting a bunch of cats, for example, you really end up having to implement that in the getQuerySet method on the view, on the view set, which is one of the things that we're going to talk about hopefully making better in the future. But then you see the hasObject permission, which where you can kind of define, does this user have permission to touch this object, is pretty straightforward, right? Is this request user the owner of this cat object? There you go. And again, you'll do this for all of the different components in your application that you care about. All right, so to put it all together, we need a couple more power tools. The first is a field restriction helper, and I'll walk you through this. But basically what we want out of this is, remember I mentioned, if you want your users to be able to set their name on their account, but you don't want them to be able to set the super user flag, this is how we're going to accomplish that sort of thing. We're going to, it's basically, it ends up being a class constructor or a class factory. I've capitalized this to make it look like a class, I think that looks nice in the final product, but technically this is a function, if that bugs you when you do this, you can go ahead and name it lowercase. But yeah, so you're going to have a function that takes a set of fields, right? So like the name field, but not the super user field. And what it's gonna do is it's going to construct that permission class for you on demand. It's going to create a set out of the fields and save that for later. And then that permission class, when it gets asked, does the user have permission? It's just gonna say, hey, all the fields that you're talking about in this request, are they a strict subset of the allowable fields that this was created with, right? So you can say, if you pass in, you do an is fields and you pass in just the name field, then anyone who ever tries to touch the super user flag will get denied by this permission, right? And you do essentially the same thing under the has object permission. And then you return the permission class. Awesome, so now we can restrict the columns that you're accessing. This is a tool that, as you can see, this is a basic version of it. It's relatively straightforward to put together yourself, but it's also something that we've written and we'd like to open source, so hopefully we can do that soon for you guys. We'd love more batteries to be just out there and ready to use. So the last power tool we need is this thing called REST condition. So you can pip install REST condition. And this is really the crux of everything, right? It gives you these composers, these ands and ors and nots that you use to put these pieces together into more complicated permissions, right? So you could combine two things with an or and you could describe a permission as if you have foo perm and not bar perm, or if you have baz perm, then you have this permission, right? And so let me show you an example of how we build a relatively complex permission structure out of these tiny pieces and this REST condition stuff. So we've got a view set here, right? We're gonna view some cats. It's gonna have a lot of other stuff. If you've written Django REST framework stuff, this will have, you know, this view set will have lots of other things defined in it, but what we care about is this permission classes where we're defining it at a base as this or. And this is a pattern that you'll end up repeating again and again. The base is just oring together a bunch of different sets of permissions. You know, different kinds of people have different kinds of access and that's what you're describing here. So for example, this first one is if it's a get, head or option, so effectively read only, and you're an authenticated user, great, you're good to go. Or if it's a post or a patch and you're the owner of the cat and you're only touching the hair or grumpiness level, then you're good to go.  And so you can see this is, you know, it's not totally short, it's not totally easy, but it's a lot less messy and a lot less complicated than the alternative, which is writing all of those things again and again for every view set, right? For every set of permissions. So these kinds of composable things, and you know, it makes it much more readable, much more maintainable, to have these things as kind of composable base permission classes. All right, so let's talk a little bit about the world of tomorrow, right? How can the world be better if we were to build some tooling around this? So let's first give a quick overview of kind of the problems that exist here. So there are a few things that I think still plague us, even with these kind of small composable permissions. One is everything's endpoint based, right? We defined this on the view set class, right? Which roughly analogous to an endpoint, the cat's endpoint of your API, right? I think the easier way to reason about this stuff is to have it be role-based, right? Role-based permissions. So if you are a super user, here's your list of permissions. If you're a cat owner, here's your list of permissions. And then those all get combined, but they get defined at a role-based level, right? Much easier to reason about. Another thing that plagues us is this code is still scattered, right? You saw we've got, has permission, we've got has object permission. Some of it had to go in get query set, and it's still scattered throughout every single view set definition, all of those little composable permissions. It's in lots of different places. And centralizing all of the permission code in one common place, I think would help a lot in kind of reasoning about it, right? It's all the right there. As I mentioned, batteries aren't entirely included here. A lot of the authentication schemes are. But that is field thing. There are a lot of other pieces of this that we've had to write internally. We're working to open source those, but in the meantime, right? These batteries are not really included. And the default is confusing, right? Do you default have permission or not have permission, right? The more secure option is default, no. You don't have permission. But the way this is working, it's sort of confused. In some ways it's one, in some ways it's the other. And I think it'd be helpful to just standardize. No one has any permissions unless you explicitly say so, right? So I wanna tease, imagine what this might look like. This is a, none of this code has been written underneath the, none of the code that would actually run this has been written, but I wanna give an example of maybe what this might look like, right? Just to kind of tease the idea. And hopefully if anyone here is interested in this, I'm gonna be spending the rest of the week hacking on this and trying to get something together. If you're interested in helping out, I'd love your help. I'd love to make this a better situation for everybody. But this is sort of a V1 idea of what the world could look like, right? You're defining a role-based permission. So anonymous user here, right? You're telling me is it active, right? For this request, is this role active? And then you just define the permissions there, right? So in this case for the cat endpoint, you can list or retrieve, but because it's default, no permissions, you can't post, you can't patch, you can't delete, right? And this would go on, of course, for other permissions and you'd go on and define other roles as well. So there's a lot of nuance that isn't included here. There's a lot that still needs to be figured out and kind of the way this would be implemented. But I think making this whole ecosystem a lot easier to reason about, easier to maintain is gonna plug up some serious security holes. I know, even with these composable permissions, we've had security polls and I wanna save people from that. I think that's partly our fault, right? We wrote the code, but partly the fault of the tools. The tools weren't helping us write secure code. So that's what I want for us. And like I said, if you are interested in helping, come find me. So thanks so much, I'm Jeff. I have to give a quick plug to choose because they paid for me to be here. So if you know anyone in San Francisco who wants better lunches at work, let us know. And yeah, that's it. Thanks so much.


Alright, this course generally, especially for those of you who are really interested in mechanical engineering, or civil engineering, this will lead directly into a course called structures. This course actually goes by several names, in fact enough names that I'm not even sure what we call it in the catalog, but it goes by several names, one of which is mechanics of materials. We're going to look at the physical properties of a material and its response to load. So it's also called strength of materials, it's also called things like deformation of elastic solids. If you think about it, that's exactly what we want structural materials to do. We want them to be able to flex under loads, and when those loads are released they return back to their original condition, ready to take the next load that comes in. You can do something more than what you do when you come into class, and the building, whether you know it or not, actually flexes under the load of us being in here when we weren't in here half an hour ago. And when we leave the building, the building will return to its original unloaded state. Actually it's sort of preloaded because the structural members of this building are holding everything above them, which includes floor, walls, and ceiling, as well as a lot of general mechanical stuff, things up there. So this course goes by a lot of names, but it does come directly off of the statics we did last fall. So everything we did there is going to lead directly into what we're going to need to do here. The very first thing we're going to have to determine is what the external loads are, and then from those external loads we're going to do exactly what we did part way through statics where we determine the internal loads in the material. That's the static response of the material itself such that there is internal shear, internal moments. We're going to also add some other types of loads to this, and it's those loads, the material responding to the external loads that is reflected in the deflection or the deformation of the structural materials that we're going to look at in this class. So that's the basic idea of what we've got going there. These two, the statics and the strength of the materials are so closely related to each other a lot of schools put these together as a single four-hour class where we have them separate as two three-hour classes, but they're that closely linked. So our number one tools and of course will be that the forces on all our objects will sum to zero, and of course the moments will sum to zero, and that's all forces taken into account in any way whether they're internal or external to the structural piece itself. It's still going to have to be a static situation for everything that we do. So let's warm up with a real quick little statics problem and then we'll make the next step as we look into the response of the material and start to get a touch on how things actually deform under these loads. To start with, we won't look at the actual deformation. We're a couple days away from that, but we will very quickly get to that. So imagine a very simply structured object of some kind where we have two simply pinned straight members holding some kind of load there. Nothing more than we did in the static. In fact, we were doing this kind of thing pretty much in the first week of statics. We went a little bit farther with it as we went along, but pretty much we weren't doing a whole bunch more than things like this in the very first weeks of static. So it's just a little bit of warm-up, but it also allows us to make the next step as we look at very different, we take a very different viewpoint of this structure than we did in statics last term. So let's say we've got a 30 kilo Newton mode there and first thing we need to know is what are the external forces on each of these members. That's going to then allow us to look at the members themselves and see how they're going to respond to those loads. What we did in the statics was we used those external loads to figure out what the internal loading was, the response of the material to those external loads. Now we're going to look at the actual physical response of these members as they react to these loads. So it shouldn't take us too long, we realize, I hope, recognize that this is a 3, 4, 5 triangle and that means that all of the ratios of all of the forces in this are also of that same ratio. So we can figure out then based on a force balance at point B here, because that will then give us the forces in the two members, since both the members meet right there, that we can very quickly determine what the external forces are and then we can make our next step and then into this new subject matter we've got here. So that's 30 kilonewtons there, obviously, and then let's see, let's label these something, we'll call that FAD and FBC. They also must have the same ratios as that 3, 4, 5 triangle because, well, why? Let me ask you why. Why must the forces be in the same ratio of 3, 4, 5 that the geometry itself is? It has to do with the fact that they're in the same directions. Well, why are they in the same directions? They're two force members. Both of these, the two structural members, AB and BC, are both two force members. Therefore, we know immediately that the forces lie in the same direction as the members themselves. Well, more specifically in the line connecting the two pins at either end. It doesn't matter what the member does in between. The forces are directed through those two pins. So then we can figure out then what the forces are without having to do too much quick calculation because we've got the same ratio in the forces that we have in the geometry itself. That's nothing more than anything we would have done in statics the first or the second we were doing that kind of stuff. What we're going to do now is take a look at the internal forces that are caused by those loads. So if we bring this little piece over here, kind of blow it up there so that you can see it, we have this, in that case the 50 kilonewton load is acting throughout this entire piece. And in fact, it's spread over that entire cross-sectional area. We'll only draw it for the most part as a single point load. But that's just for a matter of expediency on our part. But there is a bit of a distribution of that force over that area.  Area most certainly does have something to do with it. That's not great news to you. You've got that kind of experience anyway. If you're building a deck, a dock, a wood shed or something, you don't want to do it with toothpicks. It's not going to hold. Well, you may want to do it with toothpicks. But you're not going to. There's just not enough material there to support the kind of load you're seeing. And this has to do with this cross-sectional area. A very quick word about that force distribution over that area. It's not uniform. If we look at it in different places through the piece, it tends to have sort of a distribution that's like that, where most of the force is directed through the center of the piece. It tends to drop towards the edges. We're going to treat it even more simply for the most part as uniformly distributed, but not even that. We're just going to say we have this force acting on that cross-sectional area. And we're not going to worry very much about the precise distribution of the force itself. In more advanced studies of this material, yeah, you're going to have to. But for what we're doing here and our start on this, we don't need to worry about too much more than just that there's some force in some area as we're concerned with it. So those two quantities, the internal force in a material in a structural member and its cross-sectional area are right now the two most important things that we have to concern ourselves with. Now as we look at the material and its response to this, and we're finally now bringing into account more than just the length of the member, which we looked at a lot in statics last term. We're now looking at more of what the cross-sectional area is. It should follow fairly with good fair sense that the ratio of F over A would have some import to it. It makes sense, I think, as the force goes up, things get worse for the material. As the area goes down, things get worse for the material. So the ratio of the two makes some good sense because it's their movement in opposite directions. As one goes up and the other goes down, both of those contribute to a worse case, a less advantageous situation for the material itself. What we're worried about happening in this class is things going to the point where the structure itself fails, whether the material actually breaks catastrophically or maybe it just deflects enough that the structure no longer works like it should. It's quite possible that the load could go so low even though none of the members break that the structure doesn't do what it's supposed to do in the way it's supposed to do it. So this ratio is very important to us through this class. And we call it the stress and give it the symbol sigma. Great lower case sigma. And it's the force in a member divided by the cross-sectional area that is supporting that force. More specifically, this is known as the normal stress. Remember the meaning of the word normal to us? Perpendicular. Because this is the situation where the force we're concerned with is perpendicular to the area we're concerned with. And that's indeed the case that we have here where the force is perpendicular to the area. What that should mean to you is that we can take other areas. They don't have to be normal to the axial direction of the member itself. We're going to look at areas that are taken more on an angle and see what the forces are there. We're going to find out that's very, very important because when some of these things fail, they fail not at a direction perpendicular to their own axis, but at an angle off that axis. And you've seen some of this kind of thing before. When pieces fail, they don't fail in a nice cut across the piece. They fail at some angle across the piece itself. So you've seen this kind of thing before. The units. Take a rest. David, you're working too hard here already. Chris isn't ready to work at all. The units. Sort of. Two things. One is you remember our long tradition in the physical sciences of naming recurring sets of units off dead white male German physicists. So this is known as a Pascal. One Newton spread over an area of one meter squared is known as a Pascal. It's a unit of pressure. It's the very same unit of pressure that most of you have taken physics to. So you did some fluid statics. You were looked at pressure. This is the very same unit of pressure that was used there. It's exactly what it is. This is internal pressure, if you will, in a loaded member. We typically are going to be working with very, very large forces. So it's much more likely that we'll look at kilo Pascals and mega Pascals, even giga Pascals, rather than just Pascals themselves. But that's just a matter of us taking care of the units as we work through these. Since we are American academics, we also need to look at American units. Typically, we look at them in pounds per square inch. Again, since we're talking about rather large forces for the most part and some of these structures, we'll be looking at more likely kilo Pascals. Kilo pounds, or KIP, per square inch, or also known as a KSI, which is a KIP per square inch, and KIP is 1,000 pounds, a kilo pound. So we're going to have to get used to some slightly different units because these numbers typically can get rather large. Alright, so we're looking here at the stress in a material, the force it's maintaining, divided by the area of the material that's maintaining that force, that's resisting that force, if you will. We'll typically, or the main loading we'll look at now for the first couple steps through this is either a tensile force or a compressive force. For several materials, their response to tensile loads is very much the same as their response to compressive loads. Structural steel is very much that kind of material its ability to withstand stresses is about the same whether it's intention or compression. That's not true with very other, several other common structural materials, for example wood. Wood is very good in compression. It's terrible in tension. It's a factor of somewhere around 8 to 13 difference. If you're building something, you typically don't want to hang it with wood structural members. If you're going to hang it from something, if you're going to build a shelving system that hangs from the ceiling of your garage, you're going to want to have it hang from chains or cables rather than from wood straps themselves. Concrete is also that way. Very, very good in compression, not very good in tension. Sorry, other way around. No, that's right. Very good in compression, not very good in tension. We're going to have to deal with that later in the term when we look at concrete structural members because they're very commonly used in buildings, especially a lot of modern skyscrapers. It's a very easy material to work with. It can be transported in its mixed form and then poured into the shape needed for the structure right on site. That's very, very useful to an architect or a structural engineer in putting things together. It's an ability to add an aesthetic component to your structure to make it look good as well as have it behave well under these structural loads. So we've got all those kind of things that we're going to be looking at as we go through the term. Another type of simple loading, and we've looked at it some in the statics we had before, is that a structural member can have not loads that are actually directed but are transverse to the material. Now for the simplest statics we can do on this, those two forces have to be equal for the sum of the forces to be zero. Remember it's also true of the moments must be zero. What we're talking about though when we talk about shear forces is the situation where the distance between these two is very, very small so that we're not worried about the moment that that couple is causing. We're only concerned with the shear that it's causing because if we take a look at a piece, an imaginary cut through the piece, we know that that causes internal shear forces and that can cause a different type of damage and it calls for a different response from the material itself. But it's still the ratio of the two, the force over the area on which it's acting that is our concern. This case, the force is not normal to the area but it's parallel to the area. This is known as shear stress. And since we're assuming a uniform distribution of the force across that area, we're specifically talking about average shear stress. This is the type of thing that we'll see in the pins that we're using to hold these pieces together. We never look specifically at the pin joints themselves. We just assume that whatever pin was in there was strong enough to hold it. But if we look at two members that we've pinned together, we're going to do it by probably putting a rivet or a bolt or something through the piece to hold those two structural members together. That pin itself then is under these type of forces that we have here, these shear forces here where the area of concern is right there where the maximum amount of the shear is occurring. So we're concerned with the cross-sectional area of the piece and then we're concerned with the forces that that area is supporting. I have to draw something up here. So if I draw attention, it doesn't mean that compression is not a concern. As far as the pin itself is concerned, there's no difference between a piece being in compression and a piece being in tension attached to it. The pin itself still needs to resist that internal shear no matter what the piece is, what loads it's undergoing. All right, so we're going to go to the screen here. If it comes up, good. All right, I'll give you each a copy of this. We're going to now look at that very same structural object we had before, that simple triangular piece maintaining a load of 30 kW. But now we're going to look at the pieces themselves and figure out what some of the stresses are in those pieces because the places where the stress is the greatest, assuming that a piece is made out of the same material throughout, wherever the stress happens to be, the greatest is going to be our place of greatest concern. So there's a lot of little structural pieces here and we now need to look at all of them. So we'll pick one to start with. Let's look, let's see, at the member BC, the diagonal member across the top of the piece. Now in the center of the piece, we have this cross-sectional area, a little exposed part there, for example. We have that cross-sectional area that needs to withstand the forces on there. And if I remember, that was 50 kN, was it not? And that cross-sectional area itself is, well, the piece has a diameter, you notice, of about 20 millimeters. So it has a cross-sectional area of, how do you figure out the area? We're assuming that's a circular piece. You can tell that from the type of shape that the person, the draftsman, put in. That indicates a circular piece. Same kind of thing I did here on the ends of my piece. That's a common engineering notation to indicate it is a circular cross-section. How do we figure out the area of a circle with a diameter of 20 millimeters? Five times what? Pi R squared, or Pi D squared over 4. And I've got that for you. 314 times 10 to the minus 6th meters squared. So we can figure out the stress in the piece at that cross-section by simply determining the ratio of the force to the area that's withstanding that. 50 kilonewtons in the minus 6th meter squared. What units? It's easy enough to divide those numbers. I'll give it to you. It's 159, and this is intention, so we'll tend to call that a plus. Do you figure out what units? Let everybody think. David? Joey? You don't want to think yet? It'll be 8 o'clock on the first day. 3 times 10 to the third newtons, that's a kilonewton, over, we'll call it about 3, times 10 to the minus 6th meters squared. So 50 over the 314 doesn't quite give us that. 50 over, what, 0.3, right? So that would change this to 10 to the minus, the 50 over the 0.3 will give us the 159. Is that right? So this will be now 3.14 times 10 to the minus 3. 10 to the minus 3. So we have 10 to the third over 10 to the minus 3, that's 10 to the third over 10 to the minus 3. They cancel? Of course not, they're not the same. They have to be the same to cancel. So it's 10 to the 6th. That's what's just in the newtons per meter squared or megapascals. In engineering, it has long been the tradition to keep the exponents on the scientific notation in multiples of 3. Anybody know why that's long been the tradition? Because it's certainly not necessary. We have these prefixes for just about any number. No reason we have to stick to multiples of 3. Anybody know why? The tradition is long been stick to multiples of 3 if possible. You can't possibly know. So that's why you're looking at me so puzzled. When I was a baby engineer, everything we did was done on a slide rule. A slide rule can do division of two numbers very easily, but it cannot take into account where the decimal point itself goes. That had to be done. We had to do that ourselves by doing this very type of thing, writing it down. We could do the division on a slide rule, but then we had to look at the scientific notation itself and figure out what the result was then. It's just a lot easier to do that in multiples of 3 rather than get 7s and 4s and all kinds of different things thrown in there. It was just easier to keep everything as a multiple of 3 to make life a little bit easier on the slide rule. Not a concern anymore. So it's not nearly often it's done that we keep these in multiples of 3 because you just enter the whole number on the calculator and do the division straight away and take whatever is written down. But I can't guarantee you're not going to end up working at some place where the tradition is maintained very, very closely. It could well be. It also does simplify things and it keeps the number of prefixes that we need to remember down. Killa, Mega and Giga are our main ones. We'll use the micro a little bit in a step coming up here soon. Just a little bit of history for you. I guess I should ask, does everybody know what a slide rule is? Joey, you know what? In my office I had one of those 6-foot yellow ones. That's the one I used to carry around as a friend. I used to use it instead of the calculator. Those were our calculators. In fact, one very nice thing about a slide rule is they automatically maintain the right number of significant figures in an answer because you simply cannot read a slide rule to any greater accuracy than 2 or 3 places and that's automatically maintained through the piece. One way they used to get greater accuracy, more significant figures on a slide rule is they simply built them bigger. I have my grandfather's slide rule. It's this long and it's got a magnifying glass over the slider hairline so you can read even more closely. It can be more finely divided. I imagine it was a very expensive piece. It comes in a leather embossed case with his name and gold letters on it. What? It's instrument 01. Yeah, point 01. It was a big deal and if you go on eBay, there's people that are trading in slide rules as now almost like archeological pieces. Nobody, very, very few people actually still use them. Alright, so there's other places then we need to now concern ourselves. For example, up here at the end, C, if you look at the drawing there and see what we've got, we've got the piece of NC actually flattened out a little bit so that it will then mate with the other piece there and there's a hole put through it. I'm looking at the upper end of the piece of BC, the diagonal piece that goes across here. It's actually the same thing as the end down at B. That's a concern for us because now the cross-sectional area that's maintaining the force, internal force, has changed. If we look right across there, that area still needs to withstand the 50 kilonewton load. If we look at it in cross-section, it looks something like this. There's the hole and now there's the cross-sectional area that's trying to withstand that 50 kilonewton load because the 50 kilonewton load hasn't changed anywhere along the piece but now the area has changed that's withstand that load. And so that piece is now, let's see, I think this is 40 millimeters across there, is that right? And the diameter of the pin, because that's also the diameter of the hole through that piece, make sure you know how to read these. It's that pin through there, D, that's making this hole, that's a 25 millimeter diameter hole, which means the area maintaining that 50 kilonewton load has changed. So let's see how it changes the stress in the material at that point. The force is still the 50 kilonewtons. Yeah, there's a little bit of friction between the wall attachment and that piece, but we're not concerning that ourselves. Remember, we're looking at these unless otherwise said that are freely pinned pieces. So the friction there is very, very small. So this is 40 by, what's that distance? 40 minus 25 is... Yeah, so that's 17 and a half, but there's two of them on either side so we can concern ourselves with just the full area. 40 by 15 millimeter squared, and that's 60, 600 millimeter squared. Is that right? So what's the stress in that piece? That way we can compare it to the stress in this piece. Again, this is still a tensile load, so we'll call it a plus. So the stress in that piece now, who's got the calculator out? David, you do. Did I do it right? What? The stress in the cross-section? Yeah, this is the cross-section. The 40 by 15 is right, isn't it? Isn't that the attached area? Because remember, the whole area has been removed. So it's not there to withstand and it is still at 50 kilonewtons. So the 50 kilonewton force is now only through those two areas. The pin is notwithstanding any of this tensile force. It's just holding the two pieces together. We'll have to look at the pin separately because the pin is in shear, but the member itself is in normal stress. David, what's that come out to be? Something wrong with that. That's not the number I had. What did I do? Something's wrong there. I put in 50 kilonewtons. Oh, it's the millimeters. No, no, this isn't right at all. Because the area, we also have to take into account the thickness of it, which is 20 millimeters. Then it's time for the 40 minus the 15 millimeter squared. So that didn't take into account that thickness, which is 20. So 40 minus 15 is what? 25 times 20 is 500. That's still not right. 40 minus 23. 300. No, okay, that's right. Now we're okay. Yeah, 40 minus 25. 15 is the result. It's my first day, too. Is that better? Is that now the crosshatched area that's resisting that force? Okay, that's a little bit better. So it should be about 167 megapascals. Is that about right now that we got the numbers worked out? So notice that in the center of the piece we only had just under 160. Now we've got someone over 190 as a designer your concern is more now with the end piece withstanding that load because it's under greater stress than is the center of the piece itself. Not by a lot. Typically when you design structural materials you would throw in the factor of safety of at least two anyway. But it does highlight the fact that the concern is not in the middle of the piece but at the end where the shape of the piece has been changed and is now pinned through. All right, let's see. Any questions? What else can we look at? Let's look at the piece AB now. AB you'll notice is a rectangular piece. So it's interior cross section somewhere in the center is something like that. Imagine where this cut is. It's in compression remember? I remember by 40 kilonewtons. So what now is the compressive stress in this piece through the center of the piece AB? It's got to maintain the 40 kilonewtons but over what area? It's this cross sectional area here so it's the thickness divided by the depth. Looks like it's 50 and then this is millimeters. How deep is the piece? Everybody agree with that 30? You actually have to look down at this piece here. Here's AB here and you can see then it's thickness So the area is 600 square millimeters 1500 Looks a little better. So the compressive stress in that one will give it a minus sign to indicate compression if we need to. Since we're not talking about what specifically this material is we're not directly concerned with whether it's compression or tension but we certainly will be when we specify what the material is we'll have to look at the material response in compression and in tension. So what do we get for a stress there? 26.7 One thing we're going to look at later in the term is there's a different type of failure in a piece like that that's under compression where it can deflect sideways just like a column would when it's loaded we're going to have to look at how it resists the tendency of it to bow out laterally and in what direction it'll do that. Then we have that so we can look then at at this other end here where it's now this fourth part AB now comes into a U connection and it's now the cross-sectional area on point B it's now this cross-sectional area that needs to withstand the same 40 kilonewtons that was in the rest of the piece as a whole. I think by inspection you can see that there's more area there so that's going to be less concerned in terms of failure than would the the original piece in the center of the piece. Any questions so far? Pretty straightforward. It's not too terribly different than what you might have put together yourselves anyway this idea that we're concerned with the force being exerted divided by the area that's withstanding that force makes a lot more sense to do it that way than it does the product of the two as we see. The next point of concern maybe let's look at let's look at the pin at point A we've got a U-shaped connection at the wall that's this U bracket that's mounted right on the wall and then the structural member AB fits in there and it's all pinned together now that pin A is now under shear stresses such that there's a 40 kilonewton force there and two 20 kilonewton loads there just by symmetry of it I know that it's the two 20 kilonewton loads over that pin A so if we look at this little piece here we look at that little piece there it's got a 40 kilonewton load that way from the member AB itself and we must have shear moves across that face there this by the way is called double shear hopefully obvious reasons there's shear at two places of equal size on the piece is this piece in equilibrium yes or no fill your nod yes David that piece is in equilibrium because whatever couple is caused by the 20 kilonewton is defeated by the 40 kilonewton itself so the shear shear stress then how much shear is being withstood by how much area do I put in 20 kilonewtons here or do I put in 40 what you're feeling it depends it depends on what area is put in if I put in the 20 then I put in just one of these areas withstanding that 20 if I put in the full 40 I've got two areas withstanding that that either way the ratio comes out to be the same but it's the force being resisted divided by the area resisting it in this case we have a 25 millimeter area so just one of those areas is withstanding the 20 kilonewtons if you put in the full 40 you double the area and you get the same ratio anyway what's that come out to be you got it David 491 maybe with a little bit of round off here or so I want the shear stress 20 from 25 over 2 then squared 40.7 40.7 what is that a question mark I'm not sure if they use Pascals either one it's not strictly a pressure but we still use the same 40.7 without any scientific part to it any scientific rotation part to it is mega Pascals depending on what material that is you need to look at the ability of the material to withstand the shear stress certain materials it's very very much a concern of how they react to shear stresses for example if you look at a piece of wood as a pin which is very common if any of you especially in the Adirondacks we have a lot of those timber peg homes where the girders and the joists all the structural members are held with wood pins actually driven into the holes if the grain of the wood runs this way then the wood pin is very good in shear if they cut those pins such that the wood grain ran this way then it's terrible in shear and that wouldn't last very long if you even go buy a simple simple dowel at Home Depot or Loaves all of them are with the grain this way you can't even find a piece nobody would do it it just wouldn't hold wouldn't suffice any questions there's other places that are could be of concern and we need to look if you were actually designing this you need to look at every single one of the ends as well as the places themselves for example if we look at pin B pin B is a rather interesting piece itself because because it's got several loads coming in there they all come in certain different directions for example the 30 kN which is straight down is actually over two areas that are supported by this I don't know what you call it this little bracket piece so we actually have one, two, three, four five areas of pin B that need to maintain some of the load the two skinny outside areas where that bracket is and then the two or three areas I guess that are about the same size that need to maintain where the structural pieces come in so if we try to draw these in some direction let's see on the two outside slender pieces we're drawing even the outside part of the pin that's not in contact with any area because there's no load on that there's no load on it there's no sheer concern there on those parts of the faces by symmetry we assume half of the 30 kN load is on each one of those and then the part B AV comes in this U bracket at the end of that so that's the two pieces and that's in the piece itself is in compression what was the load in that? 40 kN so there's 20 kN on each of these and then the diagonal piece itself comes down B that's just the center piece now and it's in the center piece's intention so it's pulling on the pin there and so we have those loads little difficult to draw as three dimensional things always are but that's the type of thing that's happening at pin B if we turn it on the side we'd see the two 15 loads coming down like that the two 20 kN loads doing that so the concern with this pin the pin in B is which one of those faces we have these four different faces where there's four different shears going on which one of those faces is subject to the greatest shear stress because you have to design for the greatest load in order to maintain all of the loads the area is the same let's label these these faces with some reference letters E, F, G and H what's the shear at face E actually I gotta draw that one in a little bit more on that piece there acting on that section so if I look at just the face E the first face where we're seeing shear is the face between this U-brack the load bracket and the end of the piece AB what loads are on what shear load is on that face and is that the face of concern that's maintaining just one of the 15 kilonewtons loads the same thing is going on at face H just flipped around the mirror image of it so we don't need to look at that that puts an internal shear of 15 kilonewtons at the face E that again is the load bracket pulling down on the pin and so the shear stress at face E is 15 kilonewtons and what's the area of pin B that's withstanding that 15 kilonewtons pin B is how big here's pin B 25 millimeters and so what's the shear there 30.5 looks good enough any units? alright so you get out a class question what's the shear at face F or G? they'd be the same either one what's the shear stress at face F and G it's a little bit probably easier to look at it on end because it's got the two loads like that it's only half of the loads from the members because there's two sides to maintaining it's both F and G so we're only going to put half of the loads there what's the shear and the area is still the same it's the same pin it's certainly possible I guess that we can have a pin that changes an area but we don't in this case just a simple cylindrical pin put in and then tell them got it? you ready? okay first get out a class question there's no trouble, same pin, same area but what's the shear there? once we know what the shear is we just put it in a divide it's real easy what is the shear there? is it 35? remember we don't add the magnitudes of vectors we add the vectors themselves so those two vectors added together got to be resisted by a shear across the face 25 in fact that's our 3, 4, 5 triangle again and again if you look at the two areas F and G together they're maintaining 50 kilonewms in the building area, you get the same ratio anyway and you get 50.9 make


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The Falcons have a rare chance to pick early in the first round this year. The last time they picked in the top four was in 2008 when they selected Matt Ryan third overall. New general manager Terry Fontenot and head coach Arthur Smith have nine selections and should be able to take advantage of the superior draft position to pick up help at the skill positions, defensive line, and secondary. Ryan is still an effective quarterback, but is on the back side of his career. It is possible, therefore, that the team will pick up another passer in the first round. But with San Francisco jumping ahead of them to grab their future signal caller, I project the Falcons will instead pick Florida tight end Kyle Pitts. Pitts creates mismatches whether lined up inside or outside. It would be a big boost to the passing for Ryan and whoever replaces him in a few years. I project the Falcons moving from the early second round into the late first to select the edge rusher that is highest on their board. That ball's loose! Jason Oway proved his elite athleticism at Penn State's pro day. And even though he did not earn a sack in seven games as a junior, he racked up five the previous year and has a skill set to become a thorn in quarterback sides at the next level. In the third round, Atlanta would love to add a speeding running back to pair with free agent Sinead Mike Davis in a remade backfield. Gets him into the end zone touchdown. Kenneth Gainwell from Memphis is exactly that kind of dual threat. If the team moves up to grab an edge rusher in the first round, they will likely trade away their fourth round selection in the deal. But since the Falcons would only move up a few spots, they would receive a fifth or sixth round pick in return as part of the trade. Even if the Falcons are fine with Ryan as their quarterback for the next couple of years, a young passer should be on their radar at some point mistracked. They could pick Jamie Newman from Wake Forest in Georgia in the fifth round, for example, as he has the athleticism and passing acumen to fit well in Smith's offensive system. Atlanta has three fifth round picks and two sixth round selections, but sent their seventh rounder to Miami for pass rusher Charles Harris. Look it down once again. The team will need to pick up the safety in the fifth round, as well as a cornerback, receiver and offensive line depth with their later round selections. Julio stepped on the accelerator and puts in the end zone.


All right, cyber traders welcome on back here this Wednesday April 21st shortly after 2 30 p.m. Eastern time welcome on back here for our Afternoon meeting. Let's get a quick sound check just to begin make sure everybody could hear me loud and clear Should should be good to go across the trading room side great to see Ken skip Stefan All of our students just before Ron Michael Kathleen Lewis great to see you all Including all of them all of our members joining us on social media Facebook live and YouTube welcome on back So I got to say thank you Fausto for subbing in for me yesterday I was somewhere that no one probably wants to be so without in mind Let's just got let's just hop right into today in this afternoon We have class actually finishing up today. So I want to get more focused for that For all of us that were joining me within the phase 2 curriculum earlier this morning We're gonna kind of pick up where we had left off But really interact with what we're going to be putting on our afternoon list here So the way I kind of phrase it is a The final class within the phase 2 curriculum that I teach and this would be the final class within the rotation that we go through It's essentially like a mini phase 3 So if you're a gold student platinum diamond student make sure that you join this class silver student Of course as well, especially because you won't be having access to phase 3 come next week So you want to get a little taste of what you can get going into next week join us live coming up this afternoon So hey clove one of our students Tina ended up calling it out She's been watching this. I know across this whole week and uh, like like alongside her a lot of us myself included I didn't jump in though off the pot from nine when I probably could have when I should have really Nonetheless though it popped up to a hive 924 pulled back down here a bit Hopefully this could hold the support, you know, it's a stock up five plus percent We had it on our screen just to begin here, but you know, hey, I'll put this on our main list We are very familiar with this stock over the last week and a half and You know tight spread great liquidity not expensive at all So, you know definitely going to put this on our list just to begin I want to go right from top to bottom folks We have a stock that is screaming up still and it's not the top percent gainer although that's the warrants But uh skills sklz This thing is still going And also another one that does have you know a tighter spread good volume on the book for right now Uh, it hasn't tested 1650 just yet although the high of the day 1647 I don't know the news on this stock. This just seems like a short squeeze to me I mean like there was really not much activity before the market opened up I guess you could say it was trading volume, but there was no real trend to this trade But look at this thing rip. So the news out on this. Let's see if there's any And I got like no headline here dating back to this morning Nothing in particular to today that lets this run up last headline before today was back from last monday Something to do with the nfl owning 5 percent of genius sports blah blah blah All right. Well skills. We've been following this stock more often on but we've been following this stock really from the end The last year going into this year a couple of big moves and today for right now either way news or not This is making a really nice trend going into this point in the afternoon. So Alongside clove. This will definitely make the cut All right, so I guess I'll now go from top to bottom in tradition here wbt number two percent gainer I think the news out on this was a buyout, right? There's some buyout on this. They didn't give the Cash per share transaction number. They gave the cash. They gave the full valuation I think it was like four billion plus But nonetheless typically buyouts don't move once they're announced So this ended up making a beautiful run. I mean, I was totally thrown off by that I was not expecting this to make any sort of good move after 9 30 Hey built built a beautiful trend. So I missed the boat on that but now at this point It's doing exactly what I would expect it to do Uh, you know the fact that it's at the highs it makes it seem like a good opportunity for this afternoon But I think trading 94 million shares whereas before today this company was trading on average 1.2 I don't know the float on this stock. I don't really care because at this point I'm going to move on But I guess just for anyone else that does I will check it out Actually it does have a decent float 140 million share float So what exactly does that mean comparative to like a 2.47 million share float? You know really quickly it's to say that if they want to squeeze this up if by any measure this ends up popping here Then there is a better ability for this to have more fuel left in the gas tank and for this to run but I just personally don't expect it. I mean for any other time this stock made any sort of big popper drop. What happens? Looks like back in 2020 with the pandemic took a nose done Yeah, this stock rarely has even made a big move for us in terms of news or volatility So You know what? I'm going to take the odds here and say that this stock is pretty exhausted Normally for a stock near the highs we think oh, it's going to move up higher Yes, skills is one thing this sklz. This is different So this definitely makes the cut the clove makes the cut another one I'll probably run into it here in just a moment fsr. That will probably make the cut Let's see what else we got here first avgr. Yeah This a s xc stock try saying that three times fast It's at the highs. This is at the highs the stocks trading 16 million shares total today trades roughly that much on average That's not really too excessive. You know, I'd rather focus on this Although it doesn't seem like it's that lively, you know make our list. It'll be near the bottom this as xc It's like a cheap opportunity if the stars align Oh, it'll push up here Another penny Timber unfortunately, I called this out earlier saying it made a big pop just came right back down flat flattened out Now a big drop All right, let's kind of jump through this quickly because again Our whole focus for this afternoon is really preparing to trade the clothes preparing to trade the volatile market session here so I'll kind of just jump ahead to some trades that I see here like mavis and mvis You know officially micro vision. I nickname it mvis but or mavis But uh mvis squeezing back up over the 1250 level as we speak There seems to be an order on the ask at 1254 preventing it from moving higher as of right now So definitely for right now this you know nick name it mavis micro vision though. We'll definitely put this on our list Uh, there is the fsr. Where where where was it just kind of refreshed on my scanner here fsr So I was commenting on this a second ago saying likely we would be putting this on our list And definitely I mean at the highs as we speak accelerating up beautifully now. Here's the thing though Look at the trend line that I have on this, you know chart I Feel a false breakout incoming. I feel pop and drop and coming at the least if not right from here Then maybe it goes up to 15 first Looking really strong on the way up. I know that ken picked up 18 cents just a moment ago Um, you know, maybe it goes up to 15 first But I feel like it could come right back down towards where I put this trend line I know it's not showing it's off the tippy highs here But it's off the consistent highs that we're holding well off of this peak which was really strong and Now at this point, so I'd just be mindful of that but either way I mean really strong stock on the way up for right now and just otherwise pretty volatile If it goes the other way, perhaps that could be a really good short opportunity Actually, I say that because mavis I ended up shorting from the 1250 level earlier here off this peak Notice I have the trend line here for this too. So, you know, I'm thankful I just remembered this but I ended up shorting this from 1250. I was stuck in a little turbulence early on I didn't get stopped out at least but Made for a nice drop fsr could do the same thing. It's all I'm sent Oh, I did. Okay. Good. All right. Uh, let's see what else we got here across the gainer's end here market is up once again Thankfully for right now and we'll jump to bitcoin in a minute also folks I know that there's a few of us on social media right now If you've been following myself and I do the meetings I showed bitcoin I haven't had it up since the end the last week. So I was out from tuesday. We had class on monday I was not expecting bitcoin to uh Make the big drop over the weekend. So I do want to bring that up and just show you where it's at What's to come if it drops more? Canon near the highs it looks a little slow, but good spread. We're familiar with the stock Looks like a stack of orders under or above the high of the day right off 1390 Ken says right away fsr large selling here as I'm kind of juggling both this platform and the chat board, right? Uh, let's see what else we got ocg n familiar name. Oh, no, what am I just gonna refresh here? pesky trade station Let's see what else we got ocg n Uh starting to rev back up again this stock it ended up coming out with good news over the uh pre market Ended up making a nice run up. I mean most of us were trading this early in pre market including myself I ended up getting in pretty late to the party, but still picked up 15 cents But man ended up diving off after after the market opened up ended up false breaking pop dropped right back down But hey, I mean right now this stock is still giving it a go And I know this stock has a decent float. So let me just take a quick look here Where are we out here ocg n yeah 181 million share float trading, you know 104 right now I mean, it's trading a little bit more compared to what it does on an average basis that that's for certain But hey, it still seems like it could be you know opportunistic, you know on the way up for right now If it holds resistance roughly off of and it's getting close to it But roughly off of like that 6 30 ish line 6 25 ish right over here Then if it falls breaks from there and comes down that could be another short So either way, it's pretty similar to some of the other opportunities that we have so far We'll put this on our list just given the uh Given the uh volatility here All right, so let's hop over to the loser's list folks I see a couple of us on youtube a couple of us live inside cyber group Just with some call outs here of your own. I'm just going to get to that in a second Uh dgy I want to bring up really fast I know I mentioned this at least for those of us inside the trading room For those of us on youtube, you you aren't there to hear me call this out But briefly, I know the fowstow gave us two cents on this from pre-market, but I was holding this into the after hours. Oh my goodness. I knew that they were going to have the show of an Trial You know thing out there by 4 30 it dropped off a bit. I hung in the trade But afterwards I was like, all right. Well, you know at this point. It's certainly not moving up I got out And I guess that was before more news on that came out at the time That was dangerous. That could have led to a big shake right back down and I mean, man, even today it hasn't done anything this trade the dgy Why no sort of like squeezed at cap bounce, you know pop and drop at nothing so Unfortunately, that was so good into the close yesterday and continued going but I mean cheese I You didn't expect that drop. All right. So going down the list here g o f down 10 plus percent Not a whole lot really to write home about there And also on the same end you want also this year too I would have thought this had a nice close yesterday with what happened We're not going to talk about that part of it just saying you're giving the opportunity on this stock It's provided us some huge pops in the past and moving up into the close This ended up, you know dumping off also. It's unfortunate Netflix off earnings. We're not going to day trade that uv x y inverse Etf comparative to what the market's doing Uh, this is pretty close to 100. Oh right on cue this peton trade peloton just broke down below 100 a major support level Now when I say broke below it, it's not necessarily like the break to go short The more it does the more that you think it's going to drop off more But it had a really tough time at first off the initial break You would expect that and that led to a nice squeeze up to begin but It's since just pulled back a bit more.  Otherwise, it's more of a level three to four stock minimum And you know that's saying just tight spread here too. All right So halla burdened here another stock we tend to focus on at least a bit All right, that's just about does it folks. I don't really see much else across the loser's end here I mean the market's up. I always say if there's you know, not market I wouldn't expect for there to be a whole lot on the loser's end Got from RJF, let's take a look at the TYHT trade Ooh, nice. Yeah, I definitely skipped over this damn good call Pushing up nicely now and even you know from before it's more of an afternoon move Uh looks like it's on a this definitely has a low float. That's for sure I would put a lot of money on that and if I'm wrong. Well, I didn't say how much so let's see Yeah, it's got a full 3.6 million share outstanding. So, you know, it's low to begin 2.47 million share float.  It's still, you know, holding up nicely Just if the volume continues to die out if this, you know, false breaks and dumps right back down below You know where you would enter it from Be careful. In fact, I would personally look to get out because it's very likely if that were to be the case That it could just go the complete other way dump immediately back down to where it had popped from So for right now, definitely great call TYHT. Hopefully it gives us a lot more left AMC from Mitch nice push up right now. It's not up a whole lot percentage wise So wouldn't have found it on the gainer side. That's fine. You know a good sideless stock You know, we talked about this from earlier today inside class You know the AMC trade and then it's very eager to make his next call out here MTSL nice pop There we go, Mitch. All right Pushing up nicely. This one definitely will make the cut the MTSL AMC good sideless stock though. That's for short too You know, even if I don't put this on the main list if you folks do well on this stock more consistently than not Then or more frequent than I'm tripping over my words here. If you do pretty well on this stock, then I would focus on AMC It's been a long day talking there. Pardon me for that. Uh Terry saying ccl from the from the uh cyber group room I feel like with the market up you might just get a whole lot that's pushing upward with the market ccl Let's just check out airlines cruise lines all together Uh, a al doesn't look like it's up a whole lot But that's because of the pre-market funky spike up at like seven o'clock. This is at the high of the day Uh ncl h here. I know one of us just chatted just before and looking back at the chat board norman right now So it looks just like there's a whole lot of stocks that are moving with the market moving up at least for right now into the close So, you know, it's gonna be tough for me to put every single one of them on right So for right now, I'd say this I would stick with the stocks that are on the main list But if there is one that you like know that you nail Then I would put that on your personal watch list and give it a shot Stock like b n g o ken is asking here on the chat board Ah, it's near the high of the day that is for that's for sure Plus eight and a half percent today I'm like i'm like reluctant on putting this on our main list I just feel like this isn't going to continue pushing but It's close enough to the highs for me to definitely give this at least a shot And this is one that I did go on from earlier today myself So, you know, I was even a little reluctant on putting bingo on our list here But I guess this will do for right now also kind of saying no, I was saying bingo the game. Yeah, sure All right, what else we got here uh chuck saying plug losing momentum Yeah, well, you called that out earlier is at the highs another sideless stock and if that's at the highs and f sell pretty close to there can previously calling out galt galt T sideless stock perhaps for a couple of us It's been pretty volatile over the last few days Yeah It's up six percent. It's at the highs Damn, all right See this this is where I say it's tough for me to like consolidate a watch list down to a list of like four or five For you folks That's why I say for you folks from this list to try and cut it down yourself based on your personal preferences You know, if you're more of a level of three to five trader probably going to be more focused on fsr skills Maybe mvis if you're more of a level one or two student. Hey, I mean bingo looks pretty decent ocg and looks all right still at this point So, you know, that's where I'll say like even if we have a lot of stocks on the watch list It's not hard for you to try and limit the list down yourself And you know, that's where we're going to kind of leave off going into the class later on today Rgf you're in a youtube want to give him a shout he picked up 18 cents on his call on the tyht trade he got out He was in at 660 Said the spread looks lousy took the profit. That's fine You could you could always re-enter if you feel confident enough for the stock to make another move later on And if the stock moves up without you move on to another stock, that's fun Tina's saying clove. Oh, that was from earlier. But yeah, clove is still on our list You know clove is you know volatile enough good sideless stock as is Checking out benzinga pro here pretty quickly just before we finish up here The only thing i'm looking at that I see familiar the solo stock 420 resistance 140 000 share order on the ask Definitely level one interesting All right, I guess this will make the cut too I'll kind of put this near the the bottom also kind of alongside that as xc stock from before This thing looks lifeless All right, so for right now folks say a big list like I'd said again It's for you to now kind of chop this list down to a few and start with that at least going into the next 10 15 minutes You don't want to get caught up trying to follow every single call out that We're making here in the trading room between all of our students even myself and rich and Fausto Uh, you know if there's stuff on our list that that you are very familiar with that You feel confident about entering very shortly from right now Then start with that and if that stock doesn't make the big move that you're expecting To make then at that point, you know after the next 10 minutes move on to something else Then you work together as a team inside cyber group see what else we get and then go from there All right, so for all of us on youtube facebook live I appreciate you joining me as always If you haven't had the chance to do this, please just make sure that you like subscribe notify that helps us Helps us out on youtube that's youtube.com slash cyber trading you that will also help you to know when we're going live when we're not And then alongside that if you've yet to join us live inside cyber group or live professional trading room Feel free to go right down to the link on the banner below just to get started. All right For all of us there i'm going to post the uh picks for all of us there Rich is going to post the link for class and for all of us there I look forward to it. I look forward to 305 eastern time later on today. All right folks. Take care


Frank Baini Marama has said over and over and over again that he intends to win all 50 seats. Now that is impossible in this kind of scenario where you have openly proportional representation. This system is engineered for multi-party coalition governments, you don't have a majority party winning all the seats or majority of seats. So whatever he says a coalition government or a multi-party government is very much on the cards, but the problem with the Commodore is that he doesn't like to work in an environment where you have to negotiate, discuss, arrive at consensus and compromise. Often his modus operandi is my way or the highway. So there is that problem, the polls are suggesting that his party will be the largest party in parliament but not outright majority that he will have to work with other minor parties which may win a few seats here and there. How that negotiation takes place I think is very important. Now several things can happen. If he wins in his outright well that's okay, that's fine, but if he doesn't will he pick up his bags and leave and say well people have spoken this is the verdict of the ballot box and now I am prepared to observe that, respect that. I think it's unlikely what he will likely say is look I mean all that we have done over these years these things are now in jeopardy. My mission mission is not complete so I will stay on that it's in the event that he loses he will simply you know stay on. But the other problem here the other issue that's very very important is the role of the Fiji military forces. Now under the 2013 constitution the military has the guardian role over the constitution they are charged with protecting the constitution and the country as a whole. Now a number of political parties have said including Sudehlpa the main Fijian party that they would like to review the constitution because they are unhappy with some aspects of the constitution. What the military will simply say is that under this constitution we are now constitutionally obliged to act because we want to protect this constitution and so it's a ready made situation for military intervention under the cloak of legitimacy that we are doing what the constitution is asking us to do. So there is that scenario as well. So I think we will just have to wait and see you know what kind of majority does Frank Balai Marama's party have and whether he is able to transform himself and work with other political parties if he has to.


What now? You got what you wanted after all. I have. Perhaps there is more that I want. There's more that you want. What is it? Not what? Who? What do you want? It's so forward.  I'm going to leave now. It's so forward.  Okay, let's get a little bit of a recap of where we are so far. Last time what happened was we went and we found Arabella's parents actually two times ago. But then we told Arabella last time that we ended up finding her parents and we're continuing on with a quest with Halson and Daniel, trying to find Daniel. That's where we are so far. Arabella now knows her parents are dead. She's at my camp with withers and our oath is not broken. So what we're going to do today is we are looking for Kethric Thorm's relic. So we're going to the mausoleum. We're one of the Thorm mausoleum I remember now. We're looking for Kethric Thorm's relic. I know a lot of people have said this is a really good part of the game. People are very excited about me doing this. So I hope you guys enjoy. Hey, leave a comment. Let me know what you guys think about the video. Subscribe if you guys haven't subscribed yet. How you do? Okay, let's get it. Let's let it get rolling. Do the Toll House first. Didn't we already do the Toll House? We just ran through the Toll House. Whenever we first got here, the visage of obedience. Report to the Toll Master. Pay the toll. Wait. This game is so good, man. Look at it. Look at it all. Mine. Oh, wait. What the frick? What is this? Who's this? Who are you? I require... If I give you gold, what do I get in return? You can pass. But first, you must pay. I have no more gold. I'm broke. If you cannot pay, you cannot pass. Gold. Wait, what? What the... Huh? Okay. I feel like this is a disaster. She has 600 health. Maybe there's a way that we can like five head this. Haste on the Paladin. Fancy that, Jealousus. I'm gonna hide behind him. Jealous Everest. Wait, what happened? It's an AWP. These guys are agro to me too.  Telekinesis. Throw a creature object in your mind. Maybe I just need to throw her. Come on.maybe We just need to throw her. Come on. On it. Saved. Frick. Coin helmet.  Armored and Enchanted coins. The creature's clinking emblem of Golden Greed. Everybody ran out of the armor to destroy the corns.