It is said that any body at any temperature radiates energy and hence the body is losing energy. Same way body can receive the energy from the surrounding, so the increase in temp or decrease in temp. depends on the amount of energy loss and energy gain.

To analyze this we perform an experiment in which we take a metal block of heat capacity 80J/K placed in a room at 20ºC is heated electrically. The heater is switched on when the temperature reaches 30ºC. The temperature of the block rises at the rate of 2K/s just after the heater is switched on and falls at the rate of 0.2 K /s just after the heater is switched off. Assume Newton’s law of cooling to hold.

In the light of above discussion answer the following questions:

(i) What is the power of the heater?