Question

very thin metallic shell of radius R is heated to temperature t and then allowed to cool.The rate of cooling of shell is proportional to

Answer 1

Hii dear,

# Answer- temperature difference between body and surroundings

# Newton's law of cooling-

It states that the rate of heat loss of a body is directly proportional to the difference in the temperatures between the body and its surroundings provided the temperature difference is small and the nature of radiating surface remains same.

dT/dt = k × (T2-T1)

This law doesn't mention radius/area/volume of sphere so rate of cooling is independent of radius of metal ball.

Hope that cleared your doubts...