Question

When a metal cylinder of mass 2.0 10-2kg and specific heat capacity
500Jkg-1k-1 is heated at constant power the initial rate of rise of temperature is 3.0kmin-1. After time the heater is switched off and th initial rate of fall of temperature is 0.3kmin-1. What is the rate at which the cylinder gains heat energy immutably before the heat switched off?

Answer 1

Answer:

i) Power given by heater = 160 W

ii) Power radiated by block = 16 W

iii) Power radiated by block at 25 degree C = 8 W

iv) time for which heater is on = 5.19 s

Explanation:

As we know that heat capacity of the block is given as

now we know that heat given to raise the temperature of the block is given as

now rate of heat transferred to the block is given as

so we will have

Part b)

Power Radiated by the block just after heater is switched off

Part c)

Power radiated by the block when its temperature is 25 degree C

Now we can use Newton's law of cooling

so we will have

now when block temperature is given as 25 degree C then we have

Part d)

As we know that power given by the heater is

P = 160 W

now we can use energy equations

Energy given by heater = Heat absorbed by block + heat loss

Explanation: