Practice Questions

1. Explain how atmospheric pressure is caused

The gas particles in the atomsphere have energy, so they move in random directions, when they collide with a surface, they will exert a force. This force is  the atmospheric pressure.

2. Why does the atmosphere become less dense with altitude?

At higher altitude there are fewer gas particles per unit volume. This is because there is less weight of gas from above pushing downwards. So, if there are fewer gas particles per unit volume, there is less mass of gas per unit volume and so the density decreases with altitude.

3. State the name for the type of relationship between atmospheric pressure and altitude. 

Inversely proportional.