Newton's First Law

Here we discuss about Newton’s first law of motion.

You may also be interested in Newton's Second Law of Motion

The Newton’s First Law of Motion states that:

“A body will continue to move or remain in a straight line unless an opposite force acts on it and change its position either moving or state of rest”.

During the change of motion position or state of rest position, a body opposes to change called its Inertia and it depends upon the mass of the body. The higher the mass of a body, the move inertia it has and vice versa.

For Example, when a car standing on the road, then the car in the rest position. To move the car we need to push the car or start the car with petrol. But, if we don’t have petrol, then huge force is required to change the position of the car to move it. So in this case, the car has more inertia. But when the car is moving, it is very easy to push on in the straight line, but now it is very difficult to stop the car and brings to its rest position again if the breaks of the car will fail.

When the car starts after its rest position, it will moves along the straight line unless the driver switched off the engine and then the car continue to decrease speed due to friction forces that opposes its moving position and brings the car to its rest position again. So, if there are no friction forces, then the car will continue to move along the straight line with the constant speed applied by the car driver.

Thus, we can say a body will keep on moving or remains its rest position unless an opposite force acts on it and changes its moving or rest position.