Deceleration Formula

Deceleration Formulas with Solved Examples

Deceleration also known as retardation or negative acceleration, is the acceleration acts in the opposite direction of motion and is responsible for reducing the velocity of a body.



If, u = initial velocity
v = final velocity
a = constant deceleration
t = time taken
and
s = displacement
Then equations of motion is given by:
v = u - at
s = ut - ½ at2
v2 = u2 - 2as

SI unit of deceleration is m/s2.

Example:
An object moving with a velocity of 40m/s is brought to rest in 8 seconds by a constant deceleration. Find the deceleration applied.

Ans:
Here, initial velocity(u) = 40m/s
Final velocity(v) = 0 m/s
Deceleration = a
Time = 8 s
From 1st equation of motion:
v = u - at
0 = 40 - a.8
a = 40/8
= 5 m/s2.

Question:
If an object is accelerated from rest with an acceleration of 2 m/s2 for 10s, How much deceleration is needed to bring the object to rest in 4s.