Give two examples from everyday life which show that air exerts pressure.
1. When air is pumped inside a balloon, it expands in size. This shows that the air inside exerts pressure on the wall of the balloon
2.A sealed packet of chips swells up in the mountain. This is because atmospheric pressure at higher altitudes is less whereas the packet is filled with gas at normal atmospheric pressure. It therefore swells up in the mountains, as the pressure inside the chips packet is more than the atmospheric pressure outside in the higher altitudes.