Determine the power of an electric kettle if in 6 minutes it heats water weighing 1 kg from a temperature of 22

Determine the power of an electric kettle if in 6 minutes it heats water weighing 1 kg from a temperature of 22 to a temperature of 82? The specific heat capacity of water is 4200 J / kg * C

T = 6 min = 360 s.

m = 1 kg.

C = 4200 J / kg * ° C.

t1 = 22 ° C.

t2 = 82 ° C.

N -?

Let us express the amount of heat Q that is released in the electric kettle by the formula: Q = N * T, where N is the power of the electric kettle, T is the operating time of the kettle.

The amount of thermal energy Q, which is necessary for heating water, is expressed by the formula: Q = C * m * (t2 – t1), where C is the specific heat capacity of water, m is the mass of heated water, t2, t1 are the final and initial water temperatures.

Since the thermal energy that is released in the kettle is used to heat the water, then N * T = C * m * (t2 – t1).

We express the power of the kettle N by the formula: N = C * m * (t2 – t1) / T.

N = 4200 J / kg * ° C * 1 kg * (82 ° C – 22 ° C) / 360 s = 700 W.

Answer: the power of the electric kettle is N = 700 W.