Question

Can the kinetic energy of a body be negative?

Answer 1

The kinetic energy of an object is the energy it has due to its motion in physics. It is the amount of work required to accelerate a body of a given mass from rest to a certain velocity. The body retains its kinetic energy after gaining it during acceleration unless its speed changes.

Complete answer:
Kinetic energy can only be zero or positive; it cannot be negative. This is due to the fact that kinetic energy is defined as half an object's mass multiplied by its velocity squared. Because mass is a measure of matter, it can never be negative, and velocity is always positive because it is squared.

An object's kinetic energy is the energy released as a result of its motion; an object with any form of motion has a positive amount of kinetic energy. Kinetic energy, unlike some other physics quantities like velocity, does not care about direction; it only cares about magnitude. As a result, even if an object moves in the opposite direction of what is deemed positive, the sign of the kinetic energy remains unchanged.

Note: Work, on the other hand, can be negative, as when a force is applied to reduce an object's velocity (friction is an obvious example). And the change in kinetic energy equals work. As a result, the kinetic energy change can be negative. This, however, only indicates that the item is losing kinetic energy. The values of kinetic energy are still positive.