Question

How can inertia be measured?

Answer 1

Hint: Inertia is the property of a body that opposes any agency that attempts to set it in motion or, if it moves, to alter the magnitude or direction of its velocity. Inertia is a passive property that allows a body to do nothing other than oppose active agents like forces and torques.

Complete answer:
1.The first law of motion of Newton is also cited as the law of inertia.
2.This law states that, unless an external force acts on it to change its state, a body continues to be in a state of rest or in uniform motion along a straight line.
3.We find in our everyday life that a ball rolling on the ground stops after a while. This is because the ground's frictional force acts on the ball to make changes to its state of motion.
4.A body's inertia is calculated by the body's mass. The mass is heavier, the force required is higher, the inertia is greater, and vice versa.
5.The first law of Newton, therefore, defines inertia, and it is rightly called the law of inertia.

Note:
Until an external force is applied to make it move, a body tends to remain at rest. Inertia of rest is, therefore, an inability of a body to move and stay in the state of rest. Until an external force acts on it to make changes in its direction of motion, the body tends to remain in the same direction.