Why is it incorrect to say that, when a hot object warms a cold one, the increase in temperature of the cold one is equal to the decrease in temperature of the hot one? When is this statement correct?
Solution 19E Step 1: Heat flow occurs from hotter objects to colder objects. So, we can say that the increase in heat of cold object is equal to the decrease in heat of the hot object only if there is no heat loss into the surroundings. The increase in temperature of cold object is equal to decrease in temperature of hot object is true only when there is no heat loss to the surroundings. If there is no heat loss to the surroundings, both of the systems will attain equilibrium after some time and the temperatures of both systems will be same then. Conclusion: The increase in temperature of cold object is equal to decrease in temperature of hot object is not true always if there is any heat loss into the surroundings. It is correct when there is no heat loss into the surroundings.