A room is 5.0 m long, 4.0 m wide and 3.0 m high…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
A room is m long, m wide and m high. The air in it is at Pa. Find the total translational kinetic energy of all the air molecules in the room.
Need a reminder? The key ideaShow
A molecule bouncing off a wall gives it the momentum in each hit, and hits it times each second. For a gas:
where is the total translational kinetic energy.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. Volume. .
Step 2. Energy. J.
Answer: J, or MJ. That is about the energy of a one-tonne car at m/s. We cannot use this energy, because the motion is random. It does not push in one direction.
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