Question

A train moving with velocity 20 ms⁻¹ is brought to rest by applying brakes. Calculate the retardation produced.

Answer 1

The ratardation produced on applying the brakes = -20/t

u = velocity of the train = 20 m/s

a = retardation

t = time taken to stop the train after applying the brakes

Using the formula [v = u+ at]

v= 0 (final velocity is zero)

=> 0 = 20 + at

=> a = -20/t

The value is negative because retardation is the opposite of acceleration and is always negative.