Question

A bus is travelling at 54 km/h. the drive applies brakes so that it stops uniformly in 5 seconds. Find :
(a) Its acceleration
(b) Its retardation​

Answer 1

Answer:

Acceleration is ( 0 - 15 ) / 5 = -3 m/sec^2

Explanation:

Retardation is negative acceleration.

if we know the initial velocity vi and the final velocity vf and the amount of time t over which the velocity changes, the acceleration is ( vf - vi ) / t

The initial velocity is 54 km/h which is 54000/3600 m/s = 15 m/s

The final velocity is 0 m/s

The time for the velocity to change is 5 seconds

Acceleration is ( 0 - 15 ) / 5 = -3 m/sec^2