Engineers test a closed glasshouse designed to recycle water for plants. A heater warms water in a tank. Water vapour rises to a cooled roof. Liquid water that forms on the roof falls into trays of soil containing plants. No water leaks from the glasshouse.
The water tank is kept at the same temperature in both tests. Each test lasts 10 hours.
| Roof temperature in °C | Mass of water leaving the tank in kg | Mass of water falling from the roof in kg |
|---|---|---|
| 8 | 18.0 | 14.4 |
| 18 | 18.0 | 9.0 |
Calculate the percentage of the water leaving the tank that fell from the roof when the roof temperature was 8 °C.
Compare the results at the two roof temperatures and explain how increasing the roof temperature affects the amount of fresh water available to the plants.
83 exam-style questions on AQA GCSE Biology 7.2 Organisation of an ecosystem, covering 7.2.1 Levels of organisation, 7.2.2 How materials are cycled, 7.2.3 Decomposition, and 7.2.4 Impact of environmental change (HT only). Each one has a worked solution and a mark scheme showing where the marks go.