CBSE
Class 10
Class 12
Acceleration: Acceleration is seen in non-uniform motion and it can be defined as the rate of change of velocity with time.
where, v = final velocity, u = initial velocity
If v > u, then ‘a’ will be positive (+ve).
Retardation/ Deaceleration: Deceleration is seen in non-uniform motion during a decrease in velocity with time. It has the same definition as acceleration.
Here v < u, ‘a’ = negative (-ve).