Which of the following quantities will not change for a free-falling body?

Mechanical energy is the sum of kinetic energy (energy of motion) and potential energy (energy stored in a system due to the position of its parts). The velocity of a body falling freely under the influence of gravity increases as its weight decreases. As a result, there is a decrease in potential energy but an increase in kinetic energy.  However, according to the law of conservation of energy, the total mechanical energy, i.e. the sum of potential and kinetic energy, always remains constant.