Gas Pressure: The Basics

Well, let's talk about gas

pressure

, which means that a gas is like pushing something. Well, we're in two videos. This first video is quite short and is just a basic introduction to gas

pressure

, so if you don't know anything. about is no big deal, in about five minutes you'll learn everything you need to and then in the next video we're going to talk about atmospheric pressure which is like how much the outside air pushes us in the environment and then we're going to talk about the ways we can measure gas pressure so even if you think you don't know much about gas pressure you really get it right because you deal with it a lot in everyday life if I say gas pressure.

As one of the things that comes to mind, a lot of people say like a soda bottle, you know, the soda bottle has gas pressure, like the gas inside is pushing on the bottle, which makes it very rigid and then You open the lid and all the gas. it comes out and then there's not as much pressure in there or an aerosol can is something that we know has a lot of gas pressure in there, there's a lot of gas stuff, do those things particularly when people talk about gas pressure, air pressure, one of The most common thing that comes to mind is that the correct tire pressure is really important for a tire because the higher the pressure of a tire, that's how we talk, the harder it is, so let's use a tire to think about. gas pressure and learn. a little bit more about this, okay, so on a pull tire, here's our big tire, pretty shiny, right, it's not a donut, it's a tire, okay, so this tire is full of air, because we pump air in the tire to give it more pressure than me.

What I want to do is pretend that we can look inside this tire like they are x-ray glasses and these x-ray glasses are also super magnification lenses so that we can see the things that are in this tire in a way that you know we could . It's easy to see, so let's think about the air we're pumping into this tire to increase the pressure. Air is made up of a lot of things, some nitrogen, some oxygen, argon, carbon dioxide and a couple of other things too, but these. are the main things and these guys are atoms and molecules some of them like nitrogen and oxygen our molecules are made of more than one atom some things like argon or a single atom just a single atom of argon but all of this is what makes up air So if we could magnify this millions and billions of times inside the tire, we would see all these different molecules in here, but you know how lazy I am, right?

I don't want to draw all these different molecules inside the tire because it's a hassle, okay, so what I'm going to do is abbreviate all these different types of atoms and molecules by just drawing these little round red circles and these round red circles represent can be individual atoms or things like carbon dioxide, which is actually three atoms or two nitrogen atoms, two oxygen atoms, whatever. I'm going to fill my tire with these little circles that represent the molecules or atoms of the air here and we call these particles, okay, no. It doesn't matter if they represent atoms or if they represent multi-atom molecules, they are particles, okay, so let me fill this with little circles representing good, now there would actually be billions upon billions more air particles inside of this. tire, but this gives you an idea, there is something here that I have not drawn because it is difficult to draw and that is that each of these particles, whether they are atoms or molecules, are constantly flying inside this tire, okay, this is what I want to think, you really don't like when they do the lottery numbers, there's a plastic container and it's all these ping-pong balls with the different lottery numbers inside and they're all flying around, hit it against the side of the container , that's exactly what I want you to think about when you think about the air particles inside a tire here, they're like those lottery balls, those lottery ping-pong balls that are hitting everywhere inside the tire. this. tire, they hit each other, but the most important thing is that they hit the sides of the tire, the fact that these guys are flying and I'm adding these arrows to show that they are in constant motion and They are hitting sideways, really every particle should have arrows that show their movement, but I'm lazy and don't want to have to draw them, but imagine they're all flying like these lottery balls, okay?

When these guys hit the inside of the tire, it puts pressure on it, it puts a force on that tire and that's what keeps the tire inflated, that's what keeps it hard, it's all these gas particles from the air hitting the inside of the tire. that moment, you know? A lot of times when a lot of people learn this, they think there's no way these little gas particles or atoms or molecules that I can't even see with my eyes are going to hit hard enough to really keep my tire steady so I can drive. the road with it, but that's exactly what's happening, your tires are full of air and the air hits the inside of that tire and keeps it firm, so that's the gas pressure, that's how the gas can press against something really hard. exerting pressure or force if it's something like a tire, you can inflate it.

The more gas we have in something, the more pressure it exerts, which is why something like an aerosol can has so much gas in it that it bangs against the inside of that can. it has to be made of metal, a really strong metal to hold all that gas and stop the can from leaving Britain because there's so much force, there's so much pressure that comes from all the banging and you might know that because there's so many videos. . from people doing this stupid thing on youtube, don't do it yourself, please don't do it yourself, but if you put a spray can in it and heat it up, don't do this, it explodes and it does because the hotter it gets, the more The faster the gas particles move, which means the harder they hit the sides of the aerosol can and eventually they move so fast and hit so hard that not even the metal of the aerosol can can maintain that pressure because they are hitting so hard. strong and bam, it explodes because of that pressure, so the hotter it is, the more pressure a gas exerts, the more gas you have in something, the more pressure it exerts on the inside a lot of times when we talk. about the pressure we want to be able to measure if we're using a tire you can just say oh yeah I'll just let it go I'll find a pressure gauge at a gas station and stick it on the tire it'll tell me how much pressure there is At that point I could force surgery of these gas particles.

Okay, yeah, you could use a pressure gauge for a gas station, but I want to talk about something that, um, was like one of the ways that people used to measure pressure and that's still a big problem when we're learning about pressure. , okay, and that's something called a mana meter, don't call this a man, meter, right, people see this, they say, oh, it's a mana meter like something out of a cheesy 80's dating show , now it is not a nanometer. It's a pressure gauge and here's something very simple that I can do to make a device, a pressure gauge that measures pressure.

Okay, imagine I have a glass tube and I bend this tube into a U shape. Okay, and then I fill it with water. get something very creatively called U-tube long before they had the video sharing website, you can tell whoever called it U-tube was very creative and YouTube is just this piece of glass bent with water, okay, I hold the YouTube like this and the water levels out on both sides of the U-tube. Okay, now imagine what will happen when I put a little bit of gas pressure on this side of the U-tube. You know, I could bring it closer to my mouth. and blow, you know like a fort what will happen to the water in this YouTube when I blow here, well, when I blow here, the gas that I'm blowing is going to press, it's going to surround this glass tube. and it's going to press here on the surface of the water and that's going to cause this side of the water to go down and this side of the water to go up, one of them is going to go down while the other one is going to go up and when I blow on the side of this YouTube, I'm going to get something that looks like this where now the water is low on one side and higher on the other because of the pressure that the gas I'm blowing puts on the water and pushes it down in the same way that air pushes the inside a tire and it exerts a pressure that we look at to detect the sound, so I can use a YouTube like this to measure the pressure of something, say it like my time and what I do.

It's that I take my tire, I connect my YouTube to it and I open the tire so that then the air can press here and what would end up happening the same as what happens when I press it is the air in the tire. Let me draw this so it's clear what's going on here. I took the tire and I opened it up so now the gas can flow into the tube and what would happen is now it presses not only on the inside of the tire but it presses on this water forces it down forces the water up okay and now there's a height difference between one side of the U-tube and the other and what I can do is take a ruler and I can measure this distance from the bottom water to the surface of the water and I can use this difference in the heights of the water to calculate how much pressure and how much force the gas particles exert here and therefore using YouTube I can measure the pressure as the difference between the height of the water. water is fine, so this is a very basic introduction to gas pressure, how we can use a U tube to measure.

Now that you understand this, let's move on to the next video where we'll talk about atmospheric pressure and we'll talk about how I can actually put numbers to the values ​​that we get by measuring pressure with a U-tube.