Forces, Motion, & Flying

Hi, I am Jared. Welcome to Fun Science Demos. Now the big idea that we are going to talk about today is the idea that the push and pulls of forces can do some really cool things simply with air pressure. So let us see if we can see some of those forces in action with a simple cup of water and an ordinary turkey baster. Watch to see if you can see the forces. So I am going to push the air out of the turkey baster and water pulls up into the turkey baster. And when I lift up the turkey baster, none of the water is falling out. Why? Well, because forces are in action. So why is not the water falling out of the turkey baster? But what you cannot see is that this room is filled with air and all that air has pressure. And that air is pushing up on the bottom of the turkey baster, keeping the water in there. And there is no air that is able to get into the top of the water to push it out. Well, how can I let air get into the top of the turkey baster? I can pull the red bulb off and let us see what happens. What do you think will happen? Here we go. I will pull it off as fast as I can. And the water was pushed out. All the air pressure got into the top and pushed it out of the turkey baster. But we can also do some other really cool things with this turkey baster. To do that, I am going to turn the turkey baster upside down, put it in the same glass of water, and you can see not much is happening. I have air pushing down on the water inside the cup and I have air pushing down on the water that is inside the turkey baster. If I play around with forces and push and pulls just with air pressure, I can make something really cool happen. If I can lower the pressure of the air pushing down inside this turkey baster, I wonder if I could get the water to actually come up the turkey baster and shoot out the top. Well, to do that, I am going to need to lower the pressure. And how can we lower the pressure? Well, thanks to a scientist named Daniel Bernoulli, we have an idea that might work here. You see, Bernoulli discovered that if air moves quickly enough, it can actually lower the pressure. So, if I can blow over the top of this turkey baster with air that is moving quickly enough, I should be able to lower the pressure inside the turkey baster and then watch the water come right up the top of the turkey baster. But I cannot blow across that fast enough. I need a way to get the air moving faster. And for that, I need a tool. What kind of tool? An air compressor. Check this out. This nozzle is hooked up to a tank of air and that is going to really allow me to blow air quickly. Check this out. An air compressor is exactly what I need. So, if I can blow the air across this turkey baster, I want you to watch carefully the water level rise up inside the turkey baster. We are going to see if we can lower the pressure and watch science work. Here we go. We are going to zoom in so you can watch the water level and see if it really does come up the turkey baster because we are lowering the pressure. Okay, we have zoomed in. So, now watch the water level as I blow air quickly across the top. Here we go. You can see the water level coming up. I can let it go down when I stop blowing the air. Let us do it again. Faster. All right. So, now we have zoomed out so you can get the wide angle view. Check this out. Let us lower the pressure with quickly moving air. So cool. Thank you, Daniel Bernoulli. Well, believe it or not, Bernoulli is not famous because he figured out how to spray water. Bernoulli is famous because he helped us figure out how to fly. So, let us see if we can tackle the topic of flying. To do that, I am just going to hold up this piece of paper and the paper hangs down, but there is a lot going on here. Air has pressure and air pressure does not just push down. It pushes from all directions. So, I have air pressure pushing on this side of the paper and I have air pressure pushing on this side of the paper. And if I could lower the pressure on this side of the paper, I wonder what would happen. Maybe the paper might actually lift up. Well, let us check this out. So, I am going to hold the paper. I have quickly moving air again, but I am going to blow that air over top of the Stop. Quickly moving air. Unbelievable. What is going on here? Did you notice I used the word lift? Well, what was happening as the air was quickly moving over the top of the paper, it lowered the pressure. And the lower pressure lifted up the paper and the higher pressure on the bottom pushed up the paper. Forces at work. The other thing to really look at is the shape of this paper. Do you see the curved shape of this paper? Well, that is really important. It looks a lot or it looks almost like an airplane wing to me. The top of the airplane wing is curved. Now, you may not have an air compressor at home. So, we are going to show you a neat little way that you can try to prove Bernoulli's principle of flight all on your own. And all you are going to need is a hair dryer. So, let us explain what we have here. Well, we have a hair dryer that is going to be our quickly moving air. I have a simple cardboard box and I took two bamboo skewers to poke it into the box. And now, I took that same piece of paper and I cut it down and I shaped it to be an airplane wing. So, this is going to be our little airplane wing. And I put two straws through it so it would ride up and down on my skewers. And we are going to see if we can use Bernoulli's principles to get lift on our airplane wing and see if we can actually have takeoff. Well, what is going on here? We have Bernoulli's principle at work and it all has to do with forces in motion. The push and the pulls of air pressure. The air is quickly moving over the top of my airplane wing, lowering the pressure on the top, providing lift. And the cool part is that you can try it at home with a hair dryer and a piece of paper and some bamboo skewers. We would like to thank Daniel Bernoulli for asking the right questions and doing the right experiments and trying to figure this out and coming up with something that works. Without Daniel Bernoulli, we would not be able to figure out how to fly. And all the scientists that came after him to really help us do some amazing things. If you want to learn more about forces and motion, check out our links in the video description. Thanks for watching. I wonder what would happen if we use the air compressor with our wing. Let us give it a try.