Answer: The answer is the law of conservation of energy.
Step-by-step explanation:
Law of conservation of energy: It states that the energy is neither created nor destroyed. It can be transferred from one form to another.
According to the law of calorimetry, the total heat gain by the cold body is equal to the total heat loss by the hot body. There is no loss of heat in the surrounding. Heat is a form of energy. It is transferred only from one object to another.
Therefore, calorimetry depends on the law of conservation of energy.