# Eli5: Air Pressure

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Is air pressure contained in a compressor tank the same thing as potential energy?

In: Physics

Yes, air pressure contained in a compressor tank can be thought of as a form of potential energy. When air is compressed in the tank, it stores energy in the form of increased pressure. This compressed air can then be released to do work, such as powering tools or machinery. So, in a sense, the air pressure in the tank represents potential energy that can be converted into kinetic energy when it is released and put to use.

So the easy way to think of potential energy is the energy at rest. The air inside the tank is not doing anything thus it is at rest.

Now if you open the valve the air will be in motion which a simple way to look at kinetic enery is the energy of motion or work.

Yes. Sometimes this is called PV energy since it is pressure * volume (not to be confused with photovoltaics).

Yes. You have a higher pressure area, separate from a lower pressure area. If you connect the two, you’ll get flow, which can be used to perform work. That’s definitely a potential.

Yes, you can think of it like kind of 3D spring. It can be compressed or decompressed in any direction and uses or releases energy accordingly. Even both at once, _pneumatics_.

Going a bit deeper than an ELI5, all air pressure is the force of air molecules bouncing off of each other. Imagine a bunch of little balls like you would see in a lottery machine. If you push them together, they have less space around each one, so they are going to hit each other more often and thus bounce a bit faster. That takes more energy to do, so raising the potential energy. OR you could cool them down which would slow them all down a bit. That’s why your tire sensor might go off on the first day it snows. Volume, Pressure, Temperature and how many particles you start with are all related.

The air pressure we feel is actually the weight of all of the air above your head in earth’s atmosphere. It works out to about 14.7 pounds per square inch, pushing everywhere all the time. You don’t feel that because every bit of you is pushing back just as hard. If you go up a mountain, there’s less weight above you and pressure goes down. Things also get weird when you start removing most of the molecules and you get what’s called a vacuum.