(a(i))[2]
The trapped air in the pump has a pressure of $3.8 \times 10^{5}\,\text{Pa}$, and the piston has a cross-sectional area of $6.1 \times 10^{-4}\,\text{m}^2$. Calculate the force exerted on the piston by the trapped air in the pump.
(a(ii))[1]
The student moves the handle to the right, causing the piston to drive the trapped air into the tyre. The force applied by the student is smaller than the value in (a)(i). Suggest one reason why.
(b)[3]
As the handle moves to the right, the air in the pump stays at constant temperature. Explain, in terms of its molecules, why a gas pressure increases when its volume is reduced at constant temperature.