The particles in a gas move very quickly in random directions. Collisions frequently happen between:
The effect of collisions with the container is to produce a net force acting on the container walls. This force acts at right angles to the container walls, which is detected as gas pressure. This pressure can be measured using a pressure gauge.
For example, the collisions caused by a gas trapped inside a balloon cause forces to act outwards in all directions, giving the balloon its shape.
The pressure caused by a gas can be calculated using the equation:
This is when:
Another unit of pressure is the pascal (Pa):