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An electric water heater is used to make hot water for drinks - OCR Gateway - GCSE Physics - Question 19 - 2022 - Paper 1
Question 19
An electric water heater is used to make hot water for drinks. (a) The water heater is plugged into the mains supply and turned on. Explain why the temperature of t... show full transcript
Worked Solution & Example Answer:An electric water heater is used to make hot water for drinks - OCR Gateway - GCSE Physics - Question 19 - 2022 - Paper 1
Step 1
Explain why the temperature of the water increases.
Answer
When the water heater is plugged into the mains supply and turned on, electrical energy is transferred to the heating element. This energy causes the particles in the water to vibrate more vigorously, increasing their kinetic energy. In terms of energy stores, the internal energy of the water increases, leading to a rise in temperature. The energy is stored in the thermal energy store of the water, causing a temperature increase from the heating process.
Step 2
Calculate the energy required to increase the temperature of the water.
Answer
To calculate the energy required to increase the temperature of the water, we can use the provided equation:
- Mass of water, .
- Specific heat capacity of water, .
- Change in temperature, .
Now substituting these values into the equation:
Thus, the energy required to increase the temperature of the water is 3,150,000 J.