How can you calculate the cool down time of an object that i

How can you calculate the cool down time of an object that is cooled through natural convection?

Solution

WHEN AN OBJECT IS COOLED BY NATURAL CONVECTION THE HEAT TRANSFER FROM THE OBJECT IS GIVEN BY THE FORMULA hA(temp of body - temp of surroundings).

THE ABOVE RESULT WILL BE IN \"WATTS\" OR \"JOULE/SECOND\".

ALSO THE HEAT TRANSFERRED FROM THE BODY CAN BE OBTAINED AS Q/t. WHERE

Q=mc(initial temp - final temp), c= specific heat of the body, m= mass of the body. Q is in JOULE. THEREFORE Q/t IS IN \"JOULE/SECOND\".

THEREFORE FROM ABOVE Q/t = hA(temp of body - temp of surr).

IMPLIES TIME REQUIRED FOR THE BODY TO COOL DOWN IN NATURAL CONVECTION,

t = Q/[hA(temp of body- temp of surr)]