(a)[2]
Explain how the air molecules in the bag produce pressure on the inside of the bag.
(b(i))[2]
When the bag is sealed, the air pressure inside the aircraft is $80\,\text{kPa}$ and the bag contains $500\,\text{cm}^3$ of air. When the aircraft is on the ground, the air pressure inside the aircraft is $100\,\text{kPa}$. Calculate the volume of air inside the bag when the aircraft is on the ground.
(b(ii))[2]
State two assumptions that you used in your calculation in (b)(i).