A pneumatic hatch actuator contains a fixed mass of air. The table gives measurements taken during one operation. The air has returned to its starting temperature in the final state, while the piston remains in the same position as in the compressed state.
| State | Volume of air (cm3\mathrm{cm^3}cm3) | Pressure of air (Pa\mathrm{Pa}Pa) |
|---|---|---|
| Starting state | 240 | 2.0 × 105 |
| Compressed state, before cooling | 60 | 1.0 × 106 |
| Compressed state, after cooling | 60 | Not recorded |
The area of the piston face is 2.0 × 10-3 m2.
For a fixed mass of gas at constant temperature, use p1V1=p2V2p_1V_1=p_2V_2p1V1=p2V2.
Calculate the decrease in the force exerted by the air on the piston face as it cools.
108 exam-style questions on Edexcel GCSE Physics 14.3 Gas pressure and temperature, covering 14.3.1 Gas pressure and particle motion, 14.3.2 Temperature and pressure at constant volume, 14.3.3 Absolute zero and the kelvin scale, 14.3.4 Compressing and expanding gases, 14.3.5 Volume and pressure at constant temperature, and 14.3.6 Doing work on a gas. Each one has a worked solution and a mark scheme showing where the marks go.