Newton's First Law of Motion

According to Newton's First law of motion:


Any object at rest or in uniform motion remains at rest or in uniform motion unless a force is applied on it.

What this definition really means is that any body will not change its status of rest or of uniform motion unless a force is applied on it.

For example, a ball lying on the table at rest will remain there at rest unless someone sets it rolling by applying force.

Similarly, a ball already rolling will keep rolling unless someone stops it by applying force.

Confused? Don't worry! Here is the remedy of your confusion. A rolling ball does not stop by itself. Actually an opposing force is applied on all kinds of motion on earth or in air. This force is called "Force of Friction".