Question

kg $ {m^2}{s^{ - 2}} $ represents the unit of:
(A) Kinetic energy only
(B) Work done only
(C) Potential energy only
(D) All the above

Answer 1

Hint: To answer this question we first need to understand the parameters and quantities given in the options. We will then compare their units and by comparing we can easily understand which quantities possess the given unit in the question.

Complete step by step solution:
First, we will discuss kinetic energy which can be defined as a form of energy that a particle or an object attains due to its motion. When a net force is applied on an object or particle it tends to work which transfers energy, as a result, the object speeds up and which in turn gains kinetic energy. Its unit is given as a joule which can also be given as $ kg{m^2}{s^{ - 2}} $ it is a form of energy.
Work done is same as the energy hence its unit is also same which is joules and as $ 1 $ joules can be defined as $ 1 $ newton force expanded over $ 1 $ meter and hence it can be given as the product of force and distance, as a result, the unit of work done is also given as $ kg{m^2}{s^{ - 2}} $ .
Potential energy can be defined as the stored energy that depends on the relative position of the various parts of a system. Its unit is also the same as the kinetic energy as it is also a form of energy. hence the unit of potential energy is also given as $ kg{m^2}{s^{ - 2}} $ .
Therefore the option (D) is the correct answer.

Note:
Kinetic energy can also be considered as a property of a moving particle or an object that depends on the motion as well as the mass of the particle or an object. While potential energy occurs in the system when force is exerted on the system due to the relative positions of the parts involved.