Question

The inertia of a moving body makes it:
A.Stop due to friction
B.Increase its speed
C.Decrease its speed
D.Resist a change in its state of motion

Answer 1

Hint: Inertia can be seen as inherent property of a body which opposes any force that will try to change its motion. To solve the above problem we will discuss the law of inertia also known as Newton’s first law of motion, later on different types of inertia and their properties with some examples will be discussed.

Complete answer:
Newton’s first law of motion or law of inertia states that “an object will continue to be in the state of rest or in state of motion until and unless an external force acts on it”.
Inertia of a body is measured by its mass which is responsible for the action of force or moment of inertia about some specific axis which measures the resistance to the acting torque about the same axis of rotation.
Inertia can be classified in 3 types,
Inertia of rest- inertia of rest is defined as a body will remain in a state of rest until or unless an external force applied on it.
Inertia of motion: The body will continue to be in uniform motion until or unless an external force is applied on it to change its state of motion.
Inertia of direction- It can be a subpart of inertia of motion and defined as a body will continue in the direction of motion until or unless an external force is applied on it to change its course or direction.
$\therefore $By the above definitions and statements we can say that the inertia of a moving body makes it resist a change in its state of motion.

Hence, option (D) is correct.

Note:
Moment of inertia plays the same role as mass in linear motion which is the measurement of resisting force of the body to change its motion as in linear motion or in rotational motion. Moment of inertia can be affected by density of material, shape or size of the body and axis or rotation of the body.