Question

Complete the following statement. The work done on a system
$\left( {\text{A}} \right)$ Always changes the potential energy of the system.
$\left( {\text{B}} \right)$ Always changes the kinetic energy of the system.
$\left( {\text{C}} \right)$ Always changes the momentum of a system.
$\left( {\text{D}} \right)$ Can change either the potential energy or kinetic energy of the system.
$\left( {\text{E}} \right)$ Is not related to the energy of the system.

Answer 1

-Work done on a system is the amount of the product of the applied force and the displacement due to the force.
-Work done is always related to the energy of the system. Work transfers energy from one form to another.
-For pushing something the work done is related to kinetic energy as an increase in speed increases the work done. And for compressing a spring the work done is related to the elastic potential of the spring.

Complete step by step answer:
By the definition, the work done on a system is the product of the force applied to the system and the displacement due to the force.

When we are doing work against a resistive force like gravity or spring tension the work done becomes equal to the change of the potential energy of the object.

The work done by the net force on an object equals the change in kinetic energy. Such as if we try to push a block the block gains velocity as well as kinetic energy. If we increase the force the velocity will increase and also the energy will increase.

So, the work done can change either the potential energy or kinetic energy.

Hence the right answer is in option $\left( {\text{D}} \right)$.

Note: Energy can not create, it only transforms from one to another. The total amount of kinetic and potential energy of a system is constant. Work done is always related to the energy of the system. Work transfers energy from one form to another. Depending on the force, work was done on a system. It might create a change in potential or kinetic energy, but if a change is created in P.E.(potential energy), it's also effective in K.E(kinetic energy) on that system.