An engineer measures the air temperature at different heights from the floor in a large, unventilated hall. The results are recorded in the table:
| Height from floor (m\text{m}m) | Temperature (∘C^\circ\text{C}∘C) |
|---|---|
| 0.0 | 17.0 |
| 2.0 | 18.1 |
| 4.0 | 19.5 |
| 6.0 | 20.6 |
| 8.0 | 22.0 |
Which statement explains why the temperature of the air increases with height?
The average kinetic energy of molecules is lower in warm air than in cool air.
The molecules in warm air are packed more closely together than in cool air.
Cool air is less dense than warm air, so it rises.
Warm air is less dense than cool air, causing it to rise.
73 exam-style questions on CIE IGCSE Physics 2.3.2 Convection. Each one has a worked solution and a mark scheme showing where the marks go.