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

Answer:

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

Explanation:

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

so here we will have

$\frac{dQ}{dt} = ms\frac{\Delta T}{\Delta t}$

now for copper sphere we will have

$\frac{dQ}{dt} = 50(0.4)\frac{\Delta T}{\Delta t}$

$\frac{\Delta T}{\Delta t} = \frac{1}{20}\frac{dQ}{dt}$

now for Aluminium sphere we will have

$\frac{dQ}{dt} = 25(0.9)\frac{\Delta T}{\Delta t}$

$\frac{\Delta T}{\Delta t} = \frac{1}{22.5}\frac{dQ}{dt}$

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