EVERYDAY SCIENCE

Detailed explanation-1: -If two objects at different temperatures are brought in contact with each other, energy is transferred from the hotter object (that is, the object with the greater temperature) to the colder (lower temperature) object, until both objects are at the same temperature.

Detailed explanation-2: -Energy is always transferred from the substance with the higher temperature to the one at lower temperature. As energy is transferred from the hotter substance to the colder one, the colder substance gets warmer and the hotter substance gets cooler. Eventually the two substances become the same temperature.

Detailed explanation-3: -The second law of thermodynamics explains why heat will always flow spontaneously from higher temperatures to lower temperatures. This energy flow can be harnessed by a heat engine to do useful work. Heat pumps can also force thermal energy to flow backward (from cold to hot), but these require energy input.