Deceleration Formula

Deceleration Formula

You must have noticed that often we slow down the speed of our bikes during heavy traffic when more bikes are obstructing us. So, decrease in the speed as the body moves away from the starting point is defined as Deceleration.

It is expressed as

Deceleration also known as the negative acceleration. Hence it is denoted by – a.

If starting velocity, final velocity and time taken are given, Deceleration Formula is given by

If initial velocity, final velocity and distance traveled are given, deceleration is given by


v = final velocity,

U         =  initial velocity,

t = time taken,

s = distance covered.

Deceleration Formula is used to calculate the deceleration of the given body in motion. It is expressed in meter per second square (m/s2).

Solved Examples

Question 1: An automobile moving with with a uniform velocity of 54 Kmph is brought to rest in traveling a distance of 5 m. Calculate the deceleration produced by brakes?


Given: Initial velocity u = 54 Kmph,

            Final velocity v = 0,

            Distance covered s = 5m

We know that v2 = u2 + 2as

Deceleration a = v2−u22sv2−u22s

                        = 02−5422×502−5422×5

                        = −54210−54210

               = 291.6 m/s2.

Problem 2: A car is moving with a uniform velocity of 40 kmph which is is then brought to rest by applying brakes after 20s. FInd the deceleration of the train?


Given: Initial velocity u = 40 Kmph,

          Final velocity v = 0,

          Time taken t = 20s,

          Deceleration a = 0−402200−40220

                                = −160020−160020

                                = – 800 m/s2.


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