WEBVTT - TechStuff Classic: The Six Simple Machines 0:00:04.400 --> 0:00:07.800 Welcome to tech Stuff, a production from I Heart Radio. 0:00:12.119 --> 0:00:14.920 Hey there, and welcome to tech Stuff. I'm your host, 0:00:15.080 --> 0:00:18.200 Jovian Strickland. I'm an executive producer with I Heart Radio 0:00:18.280 --> 0:00:20.560 and I love all things tech. It is time for 0:00:20.600 --> 0:00:24.280 a tech Stuff classic episode. This episode originally published February 0:00:23.960 --> 0:00:27.560 twenty three, two thousand and fifteen. It is titled The 0:00:27.680 --> 0:00:33.120 Six Simple Machines Enjoy. Have you all ever done a 0:00:33.159 --> 0:00:36.280 podcast on the six classical simple Machines? If not, that 0:00:36.400 --> 0:00:39.360 might make for an interesting topic. Oh I remember these 0:00:39.400 --> 0:00:43.720 from school? I do too, is except I don't remember them. 0:00:43.800 --> 0:00:46.640 What were they? There was the toaster, There was the 0:00:47.840 --> 0:00:51.760 what the electric camera? Yeah? I think I'm pretty sure 0:00:51.800 --> 0:00:54.520 the A T M was on their nail gun, right, 0:00:54.640 --> 0:00:57.760 that's way up there? Yeah, and uh I think, uh, 0:00:57.800 --> 0:01:00.640 I think perpetual motion. That was one was really simple. 0:01:00.640 --> 0:01:04.679 It just kept going. The machine simple and it also 0:01:04.720 --> 0:01:07.800 know as the clock. Yes, yeah, yeah, no, of course 0:01:07.959 --> 0:01:12.560 the six Simple Machines are far simpler than that, but 0:01:12.720 --> 0:01:16.560 they are really important. They form the basis of a 0:01:16.640 --> 0:01:20.360 lot of the machines that we use today, and ultimately, 0:01:20.720 --> 0:01:27.120 most importantly, they make work easier. Work is hard work 0:01:27.240 --> 0:01:30.319 is hard, work is hard to explain unless you're a 0:01:30.319 --> 0:01:32.880 physics teacher and you do it all the time. But 0:01:33.000 --> 0:01:35.200 it has been many, many years since I took a 0:01:35.200 --> 0:01:38.600 course in physics, and while I still understand and appreciate 0:01:38.680 --> 0:01:41.720 simple machines and the concepts of work and force and 0:01:41.920 --> 0:01:45.080 this sort of thing, it behooved me to do a 0:01:45.120 --> 0:01:48.320 quick refresher course before doing this podcast. We'll share your 0:01:48.320 --> 0:01:51.920 knowledge with this, Jonathan. All right, So work is force 0:01:52.080 --> 0:01:56.000 acting on an object in the direction of motion. Uh. 0:01:56.000 --> 0:01:58.840 And so you could think of it in the equation 0:01:59.000 --> 0:02:04.360 of force times distance equals work. All right. Uh. So 0:02:04.400 --> 0:02:08.200 this is why we we express work in units of 0:02:08.200 --> 0:02:11.360 force and time, such as a Newton meter and a newton. 0:02:12.000 --> 0:02:15.040 Since this raises the next question, a newton is the 0:02:15.080 --> 0:02:18.320 amount of force required to accelerate one m of mass 0:02:18.360 --> 0:02:23.080 at one per second squared. So these are the basic 0:02:23.160 --> 0:02:26.040 units we're talking about, although we'll also be talking about 0:02:26.680 --> 0:02:31.960 uh pound foot as a means of a unit of measurement. 0:02:32.000 --> 0:02:37.280 Because we're in America and we use antiquated systems of 0:02:37.400 --> 0:02:40.239 units in our measurements. Then we can't understand how to 0:02:40.360 --> 0:02:44.480 use this funky you know, metric system approach or or 0:02:44.560 --> 0:02:48.520 the standard unit approach. Okay, but wait a second, how 0:02:48.600 --> 0:02:52.720 is work different from force? So force is an agent 0:02:52.840 --> 0:02:58.560 that results in accelerating or deforming an object. So if 0:02:58.639 --> 0:03:01.640 you want to get an object to start moving, you 0:03:01.680 --> 0:03:05.280 have to apply force to it. If you want to 0:03:05.320 --> 0:03:07.720 punch a hole in a wall, you have to apply 0:03:07.880 --> 0:03:11.520 force to it. But work is the force acting on 0:03:11.560 --> 0:03:13.959 that object in the direction of motion. So it's it's 0:03:14.000 --> 0:03:18.280 it's a it's it encompasses more than just the force. Okay. 0:03:18.280 --> 0:03:21.519 So if I pushed a wheelbarrow twenty feet over a 0:03:21.600 --> 0:03:24.240 certain period of time, that would be work, right, But 0:03:24.280 --> 0:03:28.840 your actual pushing against the wheelbarrow itself is force, So 0:03:29.000 --> 0:03:31.440 you know, it's it's kind of a perspective thing in 0:03:31.480 --> 0:03:33.880 a way. But it's very important when you start talking 0:03:33.919 --> 0:03:37.920 about how much how much work and actual task is 0:03:38.440 --> 0:03:40.400 versus the amount of force that you have to do 0:03:40.920 --> 0:03:44.960 to accomplish that task. Okay, And so machines in the 0:03:45.040 --> 0:03:49.360 simplest way, are something that helps us do work easier, right, Yeah, 0:03:49.440 --> 0:03:52.280 so that we either have to do the work with 0:03:52.520 --> 0:03:57.760 less force or uh. Really, machines can change the dynamics 0:03:57.800 --> 0:04:01.240 of force and distance an interesting way, and sometimes it's 0:04:01.320 --> 0:04:05.640 ways that might seem counterintuitive to you will definitely talk 0:04:05.720 --> 0:04:09.120 about something that seems counterintuitive, at least the fort when 0:04:09.120 --> 0:04:10.880 I first thought of it, it was counterintuitive when we 0:04:10.920 --> 0:04:14.840 get to h levers, which spoiler alert are actually one 0:04:14.880 --> 0:04:19.159 of the six. But at any rate, yeah, it means 0:04:19.200 --> 0:04:21.240 that we don't have to exert as much energy when 0:04:21.279 --> 0:04:25.480 we are trying to accomplish this task, the specific type 0:04:25.480 --> 0:04:29.200 of work, whatever that might be. And that was really important. 0:04:29.200 --> 0:04:34.280 I mean, obviously in early the early days of humanity, 0:04:34.360 --> 0:04:36.760 you know, we spent most of our effort just trying 0:04:36.760 --> 0:04:40.280 to make sure we weren't dying, and anything that would 0:04:40.480 --> 0:04:43.320 save us that kind of effort meant that we could 0:04:43.800 --> 0:04:47.080 we could reserve more energy for very important things like 0:04:47.240 --> 0:04:53.120 running away. It's a big one, yeah, But at any rate, 0:04:53.560 --> 0:04:57.400 so there are four main ways that machines make work easier, 0:04:58.000 --> 0:05:01.360 and the first is that he can increase the magnitude 0:05:01.520 --> 0:05:04.719 of a force. So they essentially amplify the amount of 0:05:04.720 --> 0:05:07.440 force being applied to an object or system. So you 0:05:07.480 --> 0:05:11.080 are are exerting a certain force upon a machine, the 0:05:11.120 --> 0:05:15.240 machine amplifies that force applied to whatever the load is. 0:05:15.480 --> 0:05:18.080 That's usually what we call the the thing that you're 0:05:18.120 --> 0:05:21.719 having the machine act upon and it amplifies that force 0:05:21.880 --> 0:05:24.600 so that the load is is experiencing more force being 0:05:24.600 --> 0:05:27.200 exerted upon it than you are putting into the machine. Okay, 0:05:27.240 --> 0:05:30.080 so in early humanity terms, you might think of this 0:05:30.160 --> 0:05:33.320 as something like an AX, right, yeah, that would be one, 0:05:33.520 --> 0:05:36.240 uh you know, any or a ramp, just a simple ramp, 0:05:36.279 --> 0:05:38.919 because you would you would be exerting less force to 0:05:38.960 --> 0:05:41.080 move the object as if you wanted. Let's say you 0:05:41.080 --> 0:05:45.040 wanted to move an object, huh to a allege that's 0:05:45.080 --> 0:05:48.200 ten ft above ground level, and if you were to 0:05:48.240 --> 0:05:52.240 actually just lift that object physically, it would require a 0:05:52.279 --> 0:05:54.360 certain amount of force on your side. But if you 0:05:54.440 --> 0:05:57.720 used a ramp, it would decrease, especially a very long, 0:05:58.040 --> 0:06:01.279 gradually sloped ramp, It would decrease the amount of force 0:06:01.279 --> 0:06:03.359 you needed to get the thing moving. It would just 0:06:03.440 --> 0:06:05.760 increase the amount of distance you would have to travel 0:06:05.800 --> 0:06:07.640 to get it to where it needs to go. We'll 0:06:07.640 --> 0:06:09.760 talk more about that in a bit. Oh yeah, well, 0:06:09.760 --> 0:06:12.040 I guess an AX would actually involve more than one 0:06:12.120 --> 0:06:15.120 kind of simple machine because it has an inclined plane 0:06:15.200 --> 0:06:18.200 or a wedge on it. Yeah, I thought so, maybe 0:06:18.240 --> 0:06:20.440 what I should have said would be a club, Yeah, 0:06:20.560 --> 0:06:24.360 a club that would magnify force, right, yeah. Yeah. There's 0:06:24.400 --> 0:06:27.240 also the the idea of transferring a force from one 0:06:27.240 --> 0:06:29.640 place to another, which machines that allow us to apply 0:06:29.640 --> 0:06:33.360 a force in one place the forces transferred to another place. 0:06:33.520 --> 0:06:36.960 So uh, this can be uh we'll get into some 0:06:37.000 --> 0:06:39.440 examples a little bit later. There's also changing the direction 0:06:39.600 --> 0:06:43.000 of the force, where you may have to apply a 0:06:43.000 --> 0:06:45.480 force in one direction and it's being exerted in Another 0:06:45.680 --> 0:06:48.560 classic example of this would be a lever or a 0:06:48.600 --> 0:06:52.280 pulley where you know the classic lever where I might 0:06:52.360 --> 0:06:54.440 like it. With a classic leaver, I pushed down on 0:06:54.440 --> 0:06:57.239 one side, the other side goes up, so I'm actually 0:06:57.960 --> 0:07:01.960 pushing the opposite direction of where the force is being applied. Okay, 0:07:02.040 --> 0:07:05.239 so like a seesaw. Yeah. Then there's also the increasing 0:07:05.279 --> 0:07:08.200 the distance or speed of a force, which is a 0:07:08.240 --> 0:07:10.840 pretty simple concept. Uh. And this is the one that 0:07:10.920 --> 0:07:13.800 to me was the most counterintuitive when we get to levers, 0:07:13.800 --> 0:07:15.920 but I want to save that for when we get there. 0:07:16.560 --> 0:07:18.960 And of course, a combination of machines can create a 0:07:18.960 --> 0:07:22.480 wide array of effects, and we'll talk about some compound 0:07:22.640 --> 0:07:25.760 machines which are uh, you know it's obviously two or 0:07:25.840 --> 0:07:30.000 more simple machines put together to make something more complex. Okay, 0:07:30.040 --> 0:07:32.120 well one of these simple machines has got to be 0:07:32.160 --> 0:07:35.280 the wheel, right, well, wheel and axle to be to 0:07:35.400 --> 0:07:38.360 be specific. But yes, yeah, I guess without an axle, 0:07:38.520 --> 0:07:43.240 wheel isn't not as useful, no it you know, they're 0:07:43.280 --> 0:07:47.360 essentially POGs. Yeah, you could push it a little bit 0:07:47.400 --> 0:07:49.320 and then you'd have to keep putting it back under 0:07:49.360 --> 0:07:53.679 the thing. Yeah. In fact, that's exactly how early humans 0:07:53.720 --> 0:07:56.960 were moving large weights. They would have a collection of 0:07:57.040 --> 0:07:59.600 logs and they would lay those out on the ground, 0:08:00.360 --> 0:08:02.280 place a heavy weight on top of the logs. They 0:08:02.320 --> 0:08:04.960 pushed the heavy weight. The heavy weight would roll across 0:08:05.000 --> 0:08:07.080 the tops of those logs. But that would mean that 0:08:07.400 --> 0:08:09.520 you get closer to the edge, right, you're the the 0:08:09.600 --> 0:08:11.480 end of the object. We get closer to the last 0:08:11.960 --> 0:08:14.400 remaining log in the front. You would have to pick 0:08:14.480 --> 0:08:16.520 up the logs in the back, run around, put them 0:08:16.520 --> 0:08:19.400 down in front of everything. Was not the most efficient 0:08:19.400 --> 0:08:21.160 means of getting a heavy weight from point A to 0:08:21.240 --> 0:08:23.360 point B. I bet that was a fun job. Yeah, 0:08:23.360 --> 0:08:25.880 I mean, now, granted, when all you're trying to do 0:08:26.040 --> 0:08:29.440 is build a megalithic structure to sacrifice humans on. Well, 0:08:29.480 --> 0:08:31.920 and here's the thing, the people who were building said 0:08:31.960 --> 0:08:36.679 megalithic structures often time was not something they were really 0:08:36.840 --> 0:08:42.160 that concerned about. Yeah, but at any rate, Um, if 0:08:42.160 --> 0:08:44.200 you're looking at the wheel and axel, we believe that 0:08:44.240 --> 0:08:49.600 was invented sometime around thirty five hundred b c E. Yeah, 0:08:49.640 --> 0:08:53.080 the earliest evidence actually comes from thirty two hundred from 0:08:53.120 --> 0:08:57.840 Sumerian artifacts. And also it appears to have been independently 0:08:58.440 --> 0:09:04.640 invented in China around Okay, so not shared from the Sumerians, 0:09:04.720 --> 0:09:07.400 but different people came up with the same idea. Yes, 0:09:07.440 --> 0:09:09.840 that that seems to be the case. There are some 0:09:09.840 --> 0:09:14.400 people who suggest that no, there was one common ancestor 0:09:14.520 --> 0:09:17.600 for all wheel and axles, and that that then proliferated 0:09:17.600 --> 0:09:21.040 across the rest of the world. But the research I 0:09:21.120 --> 0:09:24.600 read suggested that in fact it did appear independently, which 0:09:24.640 --> 0:09:28.040 is kind of cool. Yeah, So this allows for obviously 0:09:28.200 --> 0:09:32.680 much easier travel and transportation. Right, it reduces the friction 0:09:32.760 --> 0:09:36.160 that you would experience when you're pushing something against the ground. 0:09:36.480 --> 0:09:38.600 That makes a lot of sense because I can imagine 0:09:38.679 --> 0:09:42.720 one of the most common work problems in the ancient 0:09:42.760 --> 0:09:45.280 world was just getting stuff from one place to another, 0:09:45.440 --> 0:09:49.760 and it probably wasn't always megalithic structure, materials, you know, 0:09:50.040 --> 0:09:53.079 moving a giant stone, just moving your supplies. You've got 0:09:53.600 --> 0:09:57.520 foods you've collected or foraged, You've got you know, tools 0:09:57.760 --> 0:10:00.600 or building materials you want to take with you. How 0:10:00.600 --> 0:10:02.439 do you get them from one place to another? I mean, 0:10:02.520 --> 0:10:04.440 if all you've got is you can carry them on 0:10:04.480 --> 0:10:07.560 your back, right, you might build a sledge or something 0:10:07.640 --> 0:10:10.160 so that now you have some sort of animal that's 0:10:10.200 --> 0:10:13.040 pulling it, but that's not very efficient. It's very slow going, 0:10:13.080 --> 0:10:15.240 and of course if you hit any terrain that's not 0:10:16.120 --> 0:10:19.760 conducive to such you know, vehicles, then you're really stuck 0:10:20.120 --> 0:10:25.120 literally in some cases. So yeah, the wheel reduces friction, right, 0:10:25.160 --> 0:10:28.040 that's the big thing it does in this in this use. 0:10:28.120 --> 0:10:29.840 There's another use for the wheel and axle that we'll 0:10:29.840 --> 0:10:31.920 talk about in a second, But when you attach it 0:10:31.960 --> 0:10:34.520 to something like a cart and you have an axle 0:10:34.559 --> 0:10:38.120 and wheel set up there, then the wheels turning reduces 0:10:38.160 --> 0:10:41.920 the friction that you experience when you're pushing this against 0:10:42.000 --> 0:10:43.920 the ground, and it reduces the amount of force you 0:10:43.920 --> 0:10:47.800 need to use to get this thing moving. Um. It's 0:10:48.040 --> 0:10:50.640 you know, pretty simple concept. And there are two different, 0:10:50.720 --> 0:10:52.800 really you know types of wheel and axles. There's the 0:10:52.840 --> 0:10:55.200 type of wheel and axle where the wheel can move 0:10:55.240 --> 0:11:00.160 freely around the axles, the axle remains stationary in act 0:11:00.160 --> 0:11:02.800 to the wheel. The wheel just rotates around the axle. 0:11:03.360 --> 0:11:06.320 And then there's the fixed that that one would be 0:11:06.320 --> 0:11:09.240 fixed to the frame of the cart, so the axle 0:11:09.360 --> 0:11:11.720 is fixed and the wheel moved right. And then they're 0:11:11.760 --> 0:11:16.080 also the type where the axle turns along with the wheel. Uh, 0:11:16.120 --> 0:11:18.000 and it has to be in some sort of bearing 0:11:18.360 --> 0:11:21.720 that will hold on and allow it this turning motion. 0:11:22.200 --> 0:11:24.160 I'm trying to think what would be the advantages and 0:11:24.240 --> 0:11:27.920 disadvantages of each. So if you have free moving wheels, 0:11:27.960 --> 0:11:31.880 each wheel can move independently. Um. But if you have 0:11:31.960 --> 0:11:37.280 wheels attached directly to the axles, then the wheels on 0:11:37.360 --> 0:11:39.640 each end of one axle will have to move together, 0:11:40.360 --> 0:11:42.680 which you know, you look at cars, Yeah, you know, 0:11:42.960 --> 0:11:46.840 if if all of our cars had each wheel moving independently, 0:11:46.880 --> 0:11:51.040 and some actually do have some four wheel independent drive, uh, 0:11:51.120 --> 0:11:54.600 then that's different than if they're all working together in concert. 0:11:54.800 --> 0:11:58.000 If you will and so yeah, I mean they're they're 0:11:58.000 --> 0:12:02.160 different use cases, and there are different advantages and disadvantages. Uh. 0:12:02.200 --> 0:12:05.280 The important thing to remember is that this simple machine 0:12:05.320 --> 0:12:08.560 is one of the things that helped revolutionize humanity and 0:12:08.640 --> 0:12:13.480 keep humanity alive and allowing it to thrive. Um. Obviously, 0:12:13.520 --> 0:12:15.720 otherwise we just went and get our stuff to where 0:12:15.720 --> 0:12:18.880 it needs to be. It would be tough. Uh. So 0:12:19.679 --> 0:12:23.440 another thing you can do with the wheel and axle besides, 0:12:23.520 --> 0:12:25.200 you know, attach it to a vehicle and have it 0:12:25.320 --> 0:12:29.480 moved through. Uh. The the wheel and axel has a 0:12:30.160 --> 0:12:36.000 multiplying force aspect to it, so the force around the axle. 0:12:36.280 --> 0:12:38.600 Think of the axle. It's kind of like a small 0:12:38.640 --> 0:12:43.160 cylinder in the center of a larger cylinder, the larger 0:12:43.160 --> 0:12:45.080 one being the wheel and the small one being the axle. 0:12:46.040 --> 0:12:51.320 The rotational force around that small cylinder is greater than 0:12:51.360 --> 0:12:54.880 the rotational force on the outer cylinder, but the distance 0:12:54.920 --> 0:12:57.679 traveled on the outer cylinder is greater than the distance 0:12:57.720 --> 0:13:02.559 traveled in the inner cylinder. Yeah. Okay, Now what that 0:13:02.600 --> 0:13:05.000 means for us is that you can use a wheel 0:13:05.200 --> 0:13:08.760 as a means of like a crank or uh, you know, 0:13:08.840 --> 0:13:12.880 a valve, something along those lines, and you can apply 0:13:13.320 --> 0:13:16.360 a small amount of force to the outside of that wheel, 0:13:16.880 --> 0:13:20.400 the force being experienced on the axle part is much greater. 0:13:20.800 --> 0:13:24.000 So if you have something that normally would be fairly 0:13:24.080 --> 0:13:26.560 tough to turn, if you have a large enough wheel, 0:13:26.600 --> 0:13:28.640 it starts to become easier and easier to turn it, 0:13:28.679 --> 0:13:31.360 which is why you start seeing things like those giant 0:13:32.040 --> 0:13:36.880 wheel like um uh handles for things like the heavy 0:13:36.960 --> 0:13:40.840 doors and submarines things like that. So, yeah, that it 0:13:41.040 --> 0:13:44.760 allows you to move much heavier machinery or gears or 0:13:44.800 --> 0:13:48.800 whatever using a small amount, relatively small amount of rotational 0:13:48.840 --> 0:13:52.400 force on a larger surface, and the multiplication of that 0:13:52.440 --> 0:13:54.960 force is what gives you the ability to do a 0:13:55.000 --> 0:13:58.320 lot of work. Yeah, I can see that. In like, say, 0:13:58.360 --> 0:14:00.800 the at the helm of an old ship, you would 0:14:00.840 --> 0:14:03.000 have a very large wheel, and I'm sure it took 0:14:03.040 --> 0:14:05.960 a lot of force to move the rudder of the ships. 0:14:06.360 --> 0:14:09.360 Having a larger wheel probably made it easier. I'm glad 0:14:09.400 --> 0:14:11.440 you brought that up. I'm glad you brought up the 0:14:11.440 --> 0:14:16.839 wheel because or the helm obviously, because that that will 0:14:16.880 --> 0:14:20.440 allow us to talk about some interesting different types of machines, 0:14:21.040 --> 0:14:23.720 not just the wheel, but our next machine, the lever, 0:14:23.960 --> 0:14:28.480 because before the helm, before the wheel of a ship, 0:14:29.120 --> 0:14:32.600 which really didn't come about until the really the late 0:14:32.600 --> 0:14:37.640 eighteenth century. Yeah, yeah, you see those wheels on ships. 0:14:37.680 --> 0:14:41.720 Those are all modern inventions. In the long run, the 0:14:41.760 --> 0:14:44.600 classic way of controlling a ship was with a tiller, 0:14:45.200 --> 0:14:48.040 which was more like a lever. So a tiller is 0:14:48.160 --> 0:14:50.360 essentially it's a it's a lever that comes out, you 0:14:50.400 --> 0:14:53.680 hold onto the end. You make small adjustments on one side, 0:14:53.720 --> 0:14:57.000 but because the way the lever is adjusted, it makes 0:14:57.080 --> 0:15:00.960 larger changes with the rudder of the ship. The helm 0:15:01.000 --> 0:15:03.440 of a ship involves a lot of other parts. It's 0:15:03.480 --> 0:15:08.320 really a compound um machine ultimately, because you've got the wheel, 0:15:08.440 --> 0:15:10.760 you've got some pulley systems that connect the wheel to 0:15:10.800 --> 0:15:13.360 the rudder. It's pretty cool. So I'm glad you brought 0:15:13.400 --> 0:15:15.120 it up. Well, you know, if you look at a 0:15:15.120 --> 0:15:18.440 wheel like that as uh, something that allows you to 0:15:18.800 --> 0:15:22.680 apply force over a greater distance to create more force 0:15:22.760 --> 0:15:25.920 on a shorter distance in the middle, it's kind of 0:15:25.960 --> 0:15:30.120 like some types of levers, like, for example, a torque wringe. Right, 0:15:30.800 --> 0:15:33.920 So if you if you have a wrench and you 0:15:33.960 --> 0:15:36.120 have a bolt that you know it's really it's really 0:15:36.240 --> 0:15:38.640 or sorry, it would be a nut. I guess a nut. 0:15:38.680 --> 0:15:41.600 And it is really hard to loosen. It takes a 0:15:41.640 --> 0:15:43.480 lot of force to do it. You can do it 0:15:43.560 --> 0:15:47.080 by having a longer handle on your wrench. The longer 0:15:47.120 --> 0:15:50.880 the handle, the easier it is to get that thing loosened. Right, 0:15:50.960 --> 0:15:53.760 And you have to travel a greater distance, uh in 0:15:53.800 --> 0:15:56.560 a circle a circle right for you to get that 0:15:56.560 --> 0:15:59.800 that nut to go one complete rotation. But it's far 0:16:00.000 --> 0:16:02.160 easier as far as the amount of force applied. I 0:16:02.240 --> 0:16:04.280 like that you pronounce it lever and I pronounce it lever. 0:16:05.040 --> 0:16:07.280 It's gonna get really interesting when we're talking about leverage. 0:16:07.520 --> 0:16:10.520 So the data data, Yeah, this is the device that 0:16:10.600 --> 0:16:13.680 gives us a leverage, and which is really how I 0:16:13.720 --> 0:16:15.400 would say it. I don't know why I say lever 0:16:15.560 --> 0:16:17.480 but then I say leverage. I just don't. I guess 0:16:17.480 --> 0:16:20.080 it's you know, it's just because that song you know, 0:16:20.160 --> 0:16:23.880 fifty ways to love your lever. Okay, never mind, you 0:16:23.920 --> 0:16:28.920 love them and then you love them. So remember that. 0:16:29.120 --> 0:16:31.480 Like we were saying, work equals force times distance, and 0:16:31.600 --> 0:16:34.800 like Joe was just pointing out, if you increase the distance, 0:16:34.880 --> 0:16:37.440 that means you you can decrease the amount of force 0:16:37.480 --> 0:16:40.680 to do the same amount of work, right, or you 0:16:40.760 --> 0:16:43.480 could increase the amount of force and decrease the amount 0:16:43.520 --> 0:16:46.320 of distance and get the same amount of work. It's 0:16:46.320 --> 0:16:49.800 those two factors that determine the amount of work that's done. 0:16:50.640 --> 0:16:53.120 So using a lever, we can change that amount of 0:16:53.120 --> 0:16:57.360 force applied. Uh. And the law of the lever proposed 0:16:57.400 --> 0:17:00.520 by Archimedes you may have heard of him, is that 0:17:00.600 --> 0:17:05.040 quote magnitudes are an equilibrium at distances reciprocally proportional to 0:17:05.160 --> 0:17:10.199 their weights. End quote. That clears everything up, but it's 0:17:10.280 --> 0:17:12.719 essentially what we're talking about. So what are the basic 0:17:12.800 --> 0:17:16.320 parts of a lever. You've got, uh, your the lever 0:17:16.359 --> 0:17:19.160 itself is the side that you apply the force to. Yeah, yeah, 0:17:19.200 --> 0:17:23.240 and then you've got something that it typically has to 0:17:23.320 --> 0:17:27.800 rest against at some point along the beam. You think 0:17:27.800 --> 0:17:29.840 of the beam as the full length of whatever the 0:17:29.920 --> 0:17:33.520 liver is. The fulcrum is the pivot point that it 0:17:33.640 --> 0:17:38.400 rests against that you you use to help uh apply 0:17:38.560 --> 0:17:45.280 force to whatever the output side is typically speaking. And uh, 0:17:45.400 --> 0:17:48.840 the way this works is depending on what side is longer, 0:17:49.440 --> 0:17:53.879 that's going to travel more distance and and apply less force. 0:17:54.119 --> 0:17:56.639 So if you have a weight, and you put the 0:17:56.720 --> 0:17:59.840 short side of a beam under that weight, and then 0:17:59.840 --> 0:18:02.080 you got a fulcrum there, and then the long side 0:18:02.119 --> 0:18:03.800 of the beam is the one that you pushed down on. 0:18:04.160 --> 0:18:07.160 You have to push further to make the weight go 0:18:07.320 --> 0:18:09.560 up the distance you wanted to go, but you're using 0:18:09.680 --> 0:18:11.400 less force than you would if you were to just 0:18:11.640 --> 0:18:16.720 lift the weight up bodily, straight up. So we thought 0:18:16.720 --> 0:18:19.960 this would be easier to understand with an example. So 0:18:20.560 --> 0:18:23.879 imagine that you've got a fifty pound weight. I'm just 0:18:23.920 --> 0:18:26.959 gonna do a little bit of metrics here just at 0:18:27.000 --> 0:18:29.639 the beginning, and then I apologize. You're just gonna have 0:18:29.680 --> 0:18:32.280 to use conversions to convert everything over because I didn't 0:18:32.320 --> 0:18:34.680 do it for everything. But if you're talking about fifty pounds, 0:18:34.720 --> 0:18:37.160 that's about twenty two point seven trams and you want 0:18:37.160 --> 0:18:40.320 to lift it up two feet, which is about point 0:18:40.400 --> 0:18:42.280 six meters. To do this, you have to do a 0:18:42.320 --> 0:18:45.200 hundred pound feet of work or one thirty five point 0:18:45.280 --> 0:18:47.920 six newt meters of work, because again it's force times distance. 0:18:48.400 --> 0:18:51.200 So you'd have the uh fifty pounds of weight times 0:18:51.240 --> 0:18:55.040 the two feet, and that gets the hundred pound foot work. Now, 0:18:55.040 --> 0:18:57.560 if you used a lever that was twenty ft long 0:18:57.600 --> 0:18:59.840 on one side and then ten feet on the other side. 0:18:59.840 --> 0:19:02.120 So so the side that you're going to apply force too, 0:19:02.160 --> 0:19:04.960 it's twice as long. And you've got a fulcrum that's 0:19:05.000 --> 0:19:07.920 just uh that's one ft tall. It would be half 0:19:07.960 --> 0:19:11.400 the amount of force you would need to lift that 0:19:11.520 --> 0:19:16.240 load than before um, so it you know, it's it's 0:19:16.359 --> 0:19:18.320 much easier. And of course if you were to extend 0:19:18.359 --> 0:19:22.320 the lever longer, it would be less and less force, 0:19:22.359 --> 0:19:24.359 but you have to travel greater distances to get it 0:19:24.440 --> 0:19:26.960 up the two feet that you want. This is why 0:19:27.080 --> 0:19:31.399 you have the famous possibly apocryphal quote, uh that our 0:19:31.440 --> 0:19:33.280 committees said that he said if he had a lever 0:19:33.359 --> 0:19:36.040 long enough, he could move the world. I guess that's 0:19:36.080 --> 0:19:39.560 probably true. Yeah, I guess, well, no, I don't probably 0:19:39.640 --> 0:19:43.960 using it would depend It would depend on what the 0:19:43.960 --> 0:19:46.760 the lever or lever was made of, wouldn't it. Because 0:19:47.119 --> 0:19:49.080 at a certain point, when you're trying to move things 0:19:49.080 --> 0:19:52.560 of great enough mass are taking enough force to move, 0:19:53.280 --> 0:19:56.080 you'd reach the breaking point of your lever, wouldn't you. Well, yeah, 0:19:56.119 --> 0:19:59.440 I mean, if you had something that was that long, 0:19:59.560 --> 0:20:04.120 unless it had incredible strength, it would uh, it would 0:20:04.119 --> 0:20:07.120 break under its own weight. We'll be back with more 0:20:07.320 --> 0:20:18.520 of the six simple machines after these brief messages. So 0:20:19.080 --> 0:20:22.080 leavers change the direction or they can change the direction 0:20:22.080 --> 0:20:24.560 of an applied force, but depends upon the input and 0:20:24.640 --> 0:20:28.160 output output forces relative to the fulcrum. And there are 0:20:28.200 --> 0:20:30.560 three classes of levers. So the one we just talked 0:20:30.560 --> 0:20:33.080 about that example, the you got the it's it's like 0:20:33.119 --> 0:20:38.439 the seesaw looking type of lever. That's a the first 0:20:38.520 --> 0:20:43.000 class style of lever. Okay, So one side of the 0:20:43.000 --> 0:20:45.480 seesaw is longer than the other side. You can use 0:20:45.520 --> 0:20:49.080 the longer side to lift heavier loads. And it also 0:20:49.200 --> 0:20:51.520 changes the direction of the applied force. That's one of 0:20:51.520 --> 0:20:54.600 the one of the elements of it. The second class 0:20:55.480 --> 0:21:00.440 is more like a wheelbarrow, which involves too simple machines. 0:21:00.480 --> 0:21:02.800 You have the wheel and axle, but you also have levers. 0:21:02.840 --> 0:21:06.960 The handles act as levers. Now in that case, the 0:21:07.000 --> 0:21:12.040 fulcrumb is on one end of the entire beam. Think 0:21:12.119 --> 0:21:14.960 of the handles as a beam. So the fulcrumb in 0:21:14.960 --> 0:21:17.760 this case the wheel is weigh on one end. Then 0:21:17.840 --> 0:21:20.440 you have the load, which is the actually little load 0:21:20.480 --> 0:21:23.679 that's inside the wheelbarrow. Then you have the handles the 0:21:23.720 --> 0:21:27.360 input that you create. So it's different from the seesaw right, 0:21:27.400 --> 0:21:29.120 where you would have the fulcrum in the center. Now 0:21:29.119 --> 0:21:31.000 you have the fulcrum on the end, then the load 0:21:31.119 --> 0:21:34.400 and then you lifting it this one. Instead of reversing 0:21:34.440 --> 0:21:36.800 the direction of the force, it's the same direction right 0:21:36.800 --> 0:21:39.520 because you're lifting up on a wheelbarrow, handles and it 0:21:39.560 --> 0:21:42.280 and it lifts the load up as well. So it's 0:21:42.280 --> 0:21:47.560 different from uh, the first class of leavers. The third 0:21:47.600 --> 0:21:51.200 class is the one that seems the most counterintuitive if 0:21:51.240 --> 0:21:56.240 you first think about it. So would the flat end 0:21:56.480 --> 0:21:59.920 of a crowbar be a second class lever because they're 0:22:00.040 --> 0:22:02.720 what you're doing is you don't have the full crumb 0:22:02.720 --> 0:22:05.679 in the middle. You're you're pressing the end against the 0:22:05.720 --> 0:22:08.920 inside of the door frame, say, and then a little 0:22:08.920 --> 0:22:12.360 bit further towards the end you're holding is what's mashing 0:22:12.359 --> 0:22:15.080 against the door and you're using it to pry like 0:22:15.160 --> 0:22:18.720 a prying action. Seems like second class levers. It is, 0:22:18.800 --> 0:22:20.359 And of course, if you were to turn the crowbar 0:22:20.400 --> 0:22:23.520 around to use the curved end be a first class 0:22:23.560 --> 0:22:26.720 just like a Claude hammer would be as well. Here's 0:22:26.760 --> 0:22:29.679 a Claude hammer to remove nails. Uh, so that's a 0:22:29.680 --> 0:22:32.159 great example. Third class levers are the ones to me 0:22:32.280 --> 0:22:35.320 that are the most counterintuitive. Um they have the fulcrum 0:22:35.440 --> 0:22:39.400