Total energy of a system is always conserved, no mater what internal and external forces on the body are present

(b) Total energy of a system is always conserved, no matter what internal and external forces on the body are present.

(c) Work done in the motion of a body over a closed loop is zero for every force in nature.

(d) In an inelastic collision, the final kinetic energy is always less than the initial kinetic energy of the system.

(b) Work done by a body against friction always results in a loss of its kinetic / potential energy.

(c) The rate of change of total momentum of a many-particle system is proportional to the external force / sum of the internal forces on the system.