Gas pressure in a closed container is caused by the frequency of collision between the gas molecules and the walls of the container. All collisions are elastic.
A molecule with a mass, m moving with a velocity v, has a momentum = mv
After colliding with the wall elastically, the momentum with it bounces back is –mv.
Change in momentum = mv – (-mv) = 2 mv. Thus, produce an impulsive force. The force acting on an area of the wall produces pressure in the container.
Gas pressure can be increased by:
- increasing the temperature of the gas
- reducing the volume of the gas.
- increasing the number of gas particles.
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