Question

Assertion - Mass is a measure of inertia of the body
Reason - Greater the mass, greater is the force required to change its state of rest or of uniform motion
A. Both reason and assertion are correct, reason is the correct answer to the assertion
B. Both reason and answer are correct but reason is not the correct explanation for assertion
C. Assertion is correct but reason is incorrect
D. Assertion is incorrect but reason is correct

Answer 1

In daily life, it can be observed that when a force is applied on a body, initially it resists its motion, and we need to apply greater force to move heavy bodies.
This phenomenon can be understood from Newton’s second law of motion. And thus, states the relationship between statement one and two.

Complete step-by-step answer:
Newton’s second law of motion states that the rate of change in a body’s momentum is equal to the force applied on it.
$\overrightarrow{F}=\dfrac{d\overrightarrow{p}}{dt}$
It can be simplified for special cases, where body’s mass doesn’t change with time as;
$\overrightarrow{F}=m\overrightarrow{a}$
Inertia- A body’s characteristic to resist the change in its state of rest or of uniform motion is known as inertia. Body’s mass is a measure of the body’s inertia. This phenomenon can be observed in daily life that heavier bodies resist its motion more than lighter bodies.
To change the state of rest or of uniform motion of the body, we need to accelerate it. According to the above stated law we can say that the required force is directly proportional to the body’s mass.
$F\propto m$
Thus, it can be said that greater the mass, greater is the force required to change the body’s state of rest or of motion.
Hence assertion and reason are correct and reason is the correct explanation for the reason.
Option A. is correct.

Note: As we have discussed inertia in case of translational motion, same property exists in case of rotational motion, it is called moment of inertia.
Moment of inertia of a body is its property to resist rotational acceleration.
Moment of inertia generally given by
$I=\sum\limits_{i}{{{m}_{i}}r_{i}^{2}}$
Where, ${{m}_{i}}$ is the mass of particles it is made up of, ${{r}_{i}}$ is the particles distance from the rotational axis.