An object is said to be in motion when its position changes with time. We describe the location of an object by specifying a reference point. Motion is relative. The total path covered by an object is said to be the distance travelled by it. The shortest path/distance measured from the initial to the final position of an object is known as the displacement.

Uniform motion

When an object covers equal distances in equal intervals of time, it is said to be in uniform motion.

Non-uniform motion

Motions where objects cover unequal distances in equal intervals of time.

Speed

The distance travelled by an object in unit time is referred to as speed. Its unit is m/s.

Average speed

For non-uniform motion, the average speed of an object is obtained by dividing the total distance travelled by an object by the total time taken.