It is an everyday observation that hot and cold objects cool down or warm up to the temperature of their surroundings. If the temperature difference ∆T between an object and its surrounding (∆T = Tobj - Tsur) is not too great, the rate of cooling or warming of the objectis proportional, approximately, to this temperature difference; that is, Where A is a constant. The minus sign appears because ∆T decrease with time if ∆T is positive and increase if ∆T is negative. This is known as Newton’s law of cooling. (a) on what factors does A depend? What are its dimensions? (b) if at some instant t=0 the temperature difference is ∆t0 show that it is ∆T= ∆T0e –ata time t later.

Shane Macguire , 9 Years ago

Grade upto college level