Question

Does the work-energy theorem violate the law of conservation of energy? Explain.

Answer 1

1. Work-energy theorem states that the net work done by all the forces acting on a body is equal to the change in its kinetic energy.
2. The law of conservation states that the total energy of an isolated system remains constant.
3. Work-Energy theorem can be mathematically represented as $W=K_f-K_i$(here, $W$ is the work done, $K_f$ is the final kinetic energy and $K_i$ is the initial kinetic energy)
4. From the above expression, it is evident that the entire work done is converted to energy. There is no creation or destruction of energy. Energy is just transformed from one form to another. Thus, the law of conservation of energy remains valid.

Hence, the work-energy theorem does not violate the law of conservation of energy.