# A hollow and a solid sphere of same radius heated. which will cool at faster rate?

1. Mar 10, 2012

### vkash

There are two sphere of same radius but one is solid and other is hollow. Both are heated to same temperature(greater than room temperature). which will cool at faster rate?

I think both the spheres will cool at same rate since hollow sphere can't loose it's heat inside it (because internal temperature is also same as that of sphere) so both the spheres have same sink so they should cool at same rate.
however after little time their rate should vary because hollow sphere may have lesser energy..
IS my explanation correct?

2. Mar 10, 2012

### xts

Re: A hollow and a solid sphere of same radius heated. which will cool at faster rat

You are right: at the same temperature both emits the same power. But the hollow one has smaller heat capacity, so - emitting the same power it cools faster.

3. Mar 11, 2012

### vkash

Re: A hollow and a solid sphere of same radius heated. which will cool at faster rat

OK!!
thanks for confirming...