Motion

Distance:

Length of actual path covered by a moving body. It is a scalar quantity because it does not have particular direction.

Displacement:

Shortest distance covered by a body in definite direction. it is a vector quantity because it also have some direction.

Difference between distance and displacement:

In this diagram a person start from A then go to B then C then D then again D to A.

Here that person cover a distance of 8 m but his displacement is 0m.If the person start from A and end at D, then distance is 6 and displacement is 2m.

Speed:

Distance travelled by a moving body in unit of time interval. Speed=distance/time. It is a scalar quantity.

Velocity

 Speed of object which is moving in a definite direction or we can say that speed with direction.

 Let suppose we say 45km\h and 45km/h west. Here 45km\h is a speed and 45km\h west is a velocity. It is a vector quantity.

The rate of change of displacement of an object with respect to time is known as velocity.

Formula of Velocity is:

Velocity=displacement/time

Acceleration:

Rate of change of velocity of the object

Acceleration=change in velocity/time.

It is a vector quantity. if velocity decrease with time then acceleration is negative and is called retardation.