Question

It is said that mass is a measure of inertia. What is exactly the meaning of ' measure' here?

Answer 1

Answer:

A body remains at rest or in motion in a straight line with uniform speed, unless it is acted upon by an external force. Thus, all objects resist the change in their state of motion. This resistance is known as the inertia of the body. Greater the inertia, greater will be the force required to bring a change in its state of rest or uniform motion. Hence, mass is a measure of inertia of the body.  

Example: a real car has greater inertia than a toy car. If we move a real car, it will be quite difficult to move because of its high inertia and larger mass. But, if we move a toy car it will move a long wave. Thus, the real car resists a change in its state better than the toy car.