Simple Machines： The Lever)

Hi, I am Jared. Welcome to Fun Science Demos. So take a look at our setup that we have today. I have a thousand gram weight. I have a meter stick, and right here I have a pivot point, and I have a spring scale that measures up to a thousand grams. Look at that spring stretch. The setup, it seems pretty simple, and actually scientists have a special name for this simple setup. They call it a simple machine, because this machine makes our work easier, and that is the big idea today. Simple machines make work easier. There are many different simple machines, but today the one that we are going to take a closer look at is the lever. To start, let us take a closer look at our spring scale. So I have a thousand gram weight, and the spring scale measures up to a thousand grams. What do you think is going to happen when I try to pick up this weight with the spring scale? We are going to zoom in and take a closer look, and let us see what happens. So I am just about ready to lift our weight. Keep your eye right here and watch what happens on our spring scale. Watch it measure the weight. Here we go. I lift up. You see the spring scale stretch, and it should be right on a thousand grams. So this spring scale showed that this thousand gram weight actually did measure a thousand grams. This spring scale is also going to show that this lever is going to make our work in lifting this weight a whole lot easier. Remember, simple machines make work easier. So let us take a closer look at our lever in action. It is very simple. It is a simple machine. I have down here my pivot point, and that allows my lever to move. Scientists call my pivot point a fulcrum. Then I have my lever, and down here is my weight. So now let us see how much this simple machine, how much our lever helps us in lifting our weight. So I am going to start by attaching my weight almost to the end of my lever. It is not quite at the end. It is almost there. Now let us see how much our simple machine helps us in lifting this weight. It is not going to help us much, but we should be able to see a difference when we measure with our spring scale. So let us take a closer look. Watch what happens when I lift up. So I am going to lift up, and let us see what our spring scale measures. I lift up, and now it looks like this 1000 gram weight is actually just at 900 grams. So when we had the weight at the end of our lever, it made my work a little bit easier. Now we change things up. We put our weight in the middle of our lever, and now we are going to take a closer look to see how much easier this lever will make our work when we go to lift our weight. So here we go. I am ready to lift using my lever. Make sure to pay attention to the spring scale so we can see if my work gets any easier. Let us go ahead and lift. My weight is off the ground, and my spring scale is measuring 500 grams. Remember, this is a 1000 gram weight, but my spring scale is measuring 500 grams. What is going on? Well, it must mean that this simple machine, this lever, is making my work a whole lot easier to do. I wonder what would happen if we moved our weight even further down my lever. What do you think will happen? Let us test it out. Slide my weight down to here, and now I am going to attach my spring scale and see if this lever will make my work even easier. Let us lift up and see what will happen. Remember, it is still a 1000 gram weight, same spring scale. What is making the difference? My lever. Let us lift this thing up and see what happens. I lift it up. It is not even at 400 grams, maybe 350 grams. This lever is making my work easier. It is taking a 1000 gram weight and making it almost feel like 350 grams. See, our whole setup of our lever, our simple machine, we have our pivot point or fulcrum, our weight right here, and I pull up on this end. It really makes me think of something that we use to make our work easier. Can you think of something that looks very similar to this simple machine, our fulcrum, our weight, and we lift up at the end? So take a look. It is a smaller version of our other lever, but I have my pivot point or my fulcrum. I have my lever. Now I just need something to hold my weight. So that is where this comes in. Put that little tray to hold my weight, and what do you know? I think, what do you think I just made? To me, I think this looks an awful lot like a wheelbarrow. A wheelbarrow is nothing more than a lever. It is a simple machine to make our work a whole lot easier. If you want to learn more about simple machines, click on our links in the video description. Science is so cool, especially when it makes our work easier. Thanks for watching.