Question

Q 19) A 2 kg of water was heated with an electric heater from T1= 20°C to T2= 100°C, which took 11

minutes. If the water received all the heat released, the heater power is approximately (Specific heat

capacity of water is cw = 4200 J/kgK.):

1) 1kW

2) 1.5 kW

3) 2 kW

4) 2.5 kW

Answer 1

The power is

$$P=\frac Qt=\frac{cm\Delta T}{t}=1000\text{ W}.$$