Physics · Oct / Nov 2022 · Paper 12 · Question 21

Air is trapped in a metal cylinder by a piston. The piston is free to move and the trapped air is at atmospheric pressure. The cylinder is in hot water. [diagram: piston, trapped air, hot water, metal cylinder] The cylinder is taken out of the water and left to cool. What happens to the mass of the air in the cylinder and its pressure as it cools?

1. Amass of air: does not change; pressure of air: does not change
2. Bmass of air: does not change; pressure of air: changes
3. Cmass of air: changes; pressure of air: does not change
4. Dmass of air: changes; pressure of air: changes

As printed in the paper