Practise explaining constant temperature through balanced energy input and loss, and distinguishing zero net transfer from no transfer with CAIE IGCSE Physics questions and mark schemes.
In some countries, the soil is too cold for plants to grow well. In these countries, plants are grown in plastic pots and kept inside. The pots, containing soil, are placed on sand. The sand is heated using an electrical heater, as shown in Fig. 4.1.
Fig. 4.1
The heating element in Fig. 4.1 remains switched on. The temperature of the sand remains constant at a value above room temperature.
Explain why the temperature of the sand remains constant.
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