Newton's first law of motion also called the law of inertia, says:
An object at rest stays at rest, and an object in motion stays in motion with the same speed and in a straight line unless acted upon by an unbalanced force.
Let's break down the key ideas:
Inertia: Inertia means that things like to keep doing what they are already doing. If something is not moving, it wants to stay still. If something is moving, it wants to keep moving in the same direction and at the same speed.
Unbalanced Force: An unbalanced force is when one force is stronger than the forces opposing it. If the forces on an object are balanced, the object won't change its motion. But if there is an unbalanced force, it can make the object start moving, stop moving, or change direction.
In Simple Terms:
This law means that objects need a push or a pull (force) to start moving, stop moving, or change direction. They can't do this by themselves.
For example:
- A ball on the ground won't move unless you kick it (apply a force).
- A rolling ball won't stop unless something like friction or a wall makes it stop (apply a force).
So, Newton's first law tells us that things need a force to change their motion!
