A technician tests a sealed piston-cylinder. In each test, the cylinder contains the same mass of air at 20 ∘C20\,^\circ\text{C}20∘C.
Both tests begin with the piston in the same position, so the air has the same initial volume. The piston is moved to the same final position in each test, giving the air the same final volume. The piston is then locked in position.
The technician records the pressure immediately after each compression and again when the air has returned to 20 ∘C20\,^\circ\text{C}20∘C.
| Compression rate | Pressure immediately after compression (kPa) | Pressure at 20 ∘C20\,^\circ\text{C}20∘C (kPa) |
|---|---|---|
| Rapid | 310 | 240 |
| Slow | 250 | 240 |
Explain the results shown in the table.
Use ideas about work, energy transfer and particle collisions in your answer.
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.