Answer:
The force which is dependent on a path and mechanical energy is changed or removed is a nonconservative force.
Explanation:
Nonconservative force is the force which is dependent on a path and potential energy is not associated with it. Mechanical energy is added or removed when work is done by a nonconservative force. The best example for a nonconservative force is friction.
Mechanical energy changes when these nonconservative forces are acted but these are not conserved. Let us tale an example, car losses kinetic energy when it is stopped by friction and dissipates this kinetic energy as thermal energy.
