Quick Revision Series

Form 4 Revision:Chapter 3:Pressure

By using kinetic theory of gases,explain how gas pressure exist in a container?
- A gas consists of molecules that moves freely & at random
- This causes the molecules to hit the container's wall frequently
-There is rate of change of momentum exerted on per unit area of the wall during each collision.
- This causes pressure to be exerted on the wall.


What instrument being used to measure gas pressure?
Bourdon Gauge

Explain atmospheric Pressure?
-The earth is developed by a layer of air or gas molecules referred as atmosphere.
-Weight of these air molecules are pushing down on the earth surface
-Thus atmospheric pressure is exerted.

How does atmospheric pressure affected by altitude? Explain your answer.
-The higher the altitude, the fewer the gas molecules are present.
-There are less weight of air molecules pushing down towards the surface area
-Therefore, less atmospheric pressure being exerted.
-As a conclusion, the higher the altitude, the lower the atmospheric pressure.