ACCELERATION

 Acceleration is defined as rate of change of Velocity. 

Ie, acceleration = change in Velocity/time

Consider a body moving with an initial velocoty(u) reaches a final Velocity (v) in time (t).

Hence velocity is charged from u to v at time t body is accelerating.

Acceleration (a) = change in Velocity/ time

a = v - u/t

Unit of acceleration is m/s²

There are two types of acceleration 

1. Positive acceleration 

If the Velocity of a body is increasing with respect to time(body is increasing the speed) then the acceleration is considered to be Positive. 

2. Negative acceleration (retardation)

If the Velocity of a body is decreasing with respect to time ( body is reducing the speed), then the acceleration is considered to be negative.  It's also called as retardation.