Question Constellation Sign up for free AQA · GCSE · Combined Science · Higher
Gas temperature and chamber pressure
Figure 12 shows a device that uses a mug of hot coffee to turn a wheel.
The hot coffee increases the temperature of the air in the chamber.
Explain how the pressure in the chamber changes.
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Marking points
- 1 State that the air particles move faster or have increased kinetic energy.
- 2 Explain that the air particles collide more often with the chamber walls, or collide with more force.
- 3 Conclude that the pressure in the chamber increases.
Full-mark answer
As the air is heated, the air particles gain kinetic energy and move faster. They collide more frequently, or with more force, with the chamber walls, so the pressure in the chamber increases.
Why this answer loses marks
The pressure changes because the air gets hotter.
This does not state that particles move faster, collide more with the chamber, or that the pressure increases.