A teacher measures the air temperature at various heights from the floor inside a high-ceilinged school gym. The results are recorded in the table below.
Height from floor (m)Temperature (∘C)016.0217.5419.0620.5821.0 \begin{array}{|c|c|}\hline\text{Height from floor (m)} & \text{Temperature } (^{\circ}\text{C}) \\ \hline 0 & 16.0 \\ 2 & 17.5 \\ 4 & 19.0 \\ 6 & 20.5 \\ 8 & 21.0 \\ \hline\end{array} Height from floor (m)02468Temperature (∘C)16.017.519.020.521.0Why does the air temperature increase as the height from the floor increases?
The particles in cool air are further apart than the particles in warm air.
Warm air is less dense than cool air, so it rises.
Cool air rises above warm air due to convection.
The particles in warm air have less average kinetic energy than the particles in cool air.
301 exam-style questions on CIE IGCSE Physics 2.3 Transfer of thermal energy, covering 2.3.1a Thermal conductors and thermal insulators, 2.3.1b Explaining thermal conduction, 2.3.2 Convection, 2.3.3a Thermal radiation, 2.3.3b Surface colour and texture, 2.3.3c Rate of emission and absorption of radiation, and 2.3.4 Consequences of thermal energy transfer. Each one has a worked solution and a mark scheme showing where the marks go.