Question

The mass of object A is 5kg that of object B is 40kg, that of object C is 38kg, and that of object D is 56kg. Which object has the greatest inertia?
(A) A
(B) B
(C) C
(D) D

Answer 1

Newton's first law of motion states that inertia of an object is the tendency of the object to remain at rest or, if moving, to continue its motion.IThe corrections directly proportional to the mass. Complete step by step answer:
Mass is a measure of inertia. The heavier the body, the greater is the force required to change its state, and hence greater is its inertia. Thus in this question, object D is having more mass that is 56kg. Hence object D has more inertia.
In the absence of net external force, the body which is in the state of rest continues to be at rest, and the body which is moving with uniform velocity continues to move with uniform velocity. The body cannot change its state by itself. This property is called inertia. Due to inertia, the body opposes the change of its state.
Hence we can conclude that mass is directly proportional to the inertia. Greater the mass of the object greatest is the mass of the body. Because more force is required to change the state of the object.

Therefore, the correct option is (D). The object D having a mass of 56kg has high inertia.

Additional information:
There are three types of inertia.
Inertia at rest: a body cannot change its state of rest by itself.
Inertia at motion: a body cannot change its state of uniform motion by itself. That is a body in uniform motion can neither accelerate nor retard on its own.
Inertia at direction: a body cannot change its direction of motion by itself. That is a body continues to move along the same straight line unless compelled by some external force to change it.
Newton’s first law gives the concepts of inertia and force. It states that everybody continues to be in its state of rest or uniform motion in a straight line unless an external force acts on it.

Note:
In simple words we can say, inertia means ‘resistance to change’.
Inertia is a measure of mass. Thus SI unit of inertia is kg.
The Law of inertia is known as Newton’s first law of motion.