The law of inertia by sir Isaac Newton is one of the most important laws of physics. The law of inertia is "An element will continue to be in a state of rest or if it is moving, the state of motion will continue until an external force act on it."
There are different types of inertia.
- The inertia of rest,
- The inertia of direction
- The inertia of motion
When a body is at rest, it will stay at rest until a force act on the body in any direction. If the body is in motion, it will continue to move in the same direction until a force is applied to the body.
Some examples of inertia are: when a lift starts suddenly. When the bus starts, we have a tendency to move back. When a lift starts to operate suddenly, we feel a jerk. People tend to move forward when a brake is applied to the vehicle.
Newton's first law is the law of inertia.