A parcel-sorting machine uses a sealed gas cushion to slow a moving platform. The gas is initially at 18 ∘C18\,^\circ\mathrm{C}18∘C. The platform compresses the gas in less than one second.
| Measurement | Pressure in kPa\mathrm{kPa}kPa | Volume in cm3\mathrm{cm^3}cm3 |
|---|---|---|
| Before compression | 400 | 80 |
| Immediately after compression | 760 | 50 |
The platform is then locked in place, so the gas remains at a volume of 50 cm3. The gas transfers energy to the surroundings until it returns to 18 ∘C18\,^\circ\mathrm{C}18∘C.
Calculate the pressure-volume product for each measurement. Give your answers in kPa cm3\mathrm{kPa\,cm^3}kPacm3.
Explain why the pressure-volume product is greater immediately after compression than before compression.
Calculate the pressure of the gas when it has returned to 18 ∘C18\,^\circ\mathrm{C}18∘C.
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.