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A 4.5-kW resistance heater in a water heater runs for 3 hours to raise the water temperature to the desired level. Determine the amount of electric energy used in both kWh and kJ.

1 Answer

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Answer:

The electrical energy is 13.5 kWh or 48600 kJ

Step-by-step explanation:

Given that,

The power of the resistance heater, P = 4.5 kW

The water heater runs for 3 hours to raise the water temperature to the desired level.

We need to find the amount of electric energy used in both kWh and kJ.

Energy = Power × time

E = 4.5 kW × 3 h

= 13.5 kWh

Since,

1 kWh = 3600 kJ

13.5 kWh = 48600 kJ

Hence, the required electrical energy is 13.5 kWh or 48600 kJ

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