In an electric kettle with a power of 2 kW, 1 kg of water was heated at 90 ° C for 3.5 minutes. Calculate

In an electric kettle with a power of 2 kW, 1 kg of water was heated at 90 ° C for 3.5 minutes. Calculate: a) the work of the current passed through the heating element of the electric kettle; b) the amount of heat transferred from the heating element to the water; c) the efficiency of the heating element.

Decision:
A = P t = 2000 * 210 = 420,000 J
Q = 4200 * 90 * 1 = 378,000 J
Efficiency = Q / A * 100% = 90%
Answer: 420,000 J; 378,000 J; 90%