What is inertia?

Hint: Newton's first law of motion is also popularly known as the law of inertia. The Law of Inertia explains the inner tendency of an object to maintain its state of rest or motion.

Complete step by step solution:
This law states that a body continues to be in the state of complete rest or in uniform motion along a straight line until and unless an external force is exerted upon the body, forcing it to change its state.

In our daily life, we find that an object like a ball rolling on the ground stops after some time. This is because the frictional force of the ground is acting on the ball to make changes in its state of motion.

The inertia of the body is measured by the mass of the body. The greater the mass of the body (heavier), the greater is the force required to change its state of motion, and hence greater is its inertia.

Additional Information:
A few examples to describe the law of inertia in our day-to-day life are as follows:
1. When a bus starts suddenly, we fall backwards. This is because the lower part of the body starts moving with the bus while the upper part tries to remain at rest.
2. Athletes run to a certain distance before taking a long jump.
3. On shaking the mango tree, the mango falls off the tree.
4. When a car rounds a curve suddenly, a driver is thrown outside of the curve

Note: Based on the various types of changes that can occur to a body, inertia is of three types:
- The inertia of rest: Tendency of a body to remain in the state of rest.
- The inertia of direction: Tendency of a body to remain in a particular direction.
- The inertia of motion: Tendency of a body to remain in a state of uniform motion.