Question

You hold a 50-g sphere of copper (c = 0.4J/(g*C)) in one hand and a 25-g sphere of aluminum ( = 0.9 J/(g*C)) in the other hand. If both absorb energy at the same rate, which will come to your body temperature first and why?

Answer 1

rate of change in temperature of copper is more than the rate of change in temperature of aluminium.

so here copper will reach to our body temperature first

Step-by-step explanation:

As we know that rate of energy absorb by the two sphere is same

so here we will have

`(dQ)/(dt) = ms(\Delta T)/(\Delta t)`

now for copper sphere we will have

`(dQ)/(dt) = 50(0.4)(\Delta T)/(\Delta t)`

`(\Delta T)/(\Delta t) = (1)/(20)(dQ)/(dt)`

now for Aluminium sphere we will have

`(dQ)/(dt) = 25(0.9)(\Delta T)/(\Delta t)`

`(\Delta T)/(\Delta t) = (1)/(22.5)(dQ)/(dt)`

So rate of change in temperature of copper is more than the rate of change in temperature of aluminium.

so here copper will reach to our body temperature first