Question

A car is running at a speed 72 km/ hr and stop at 45 second then what will be the retardation?​

Answer 1

hey mate hope it helps you...

initial velocity = 72Km/hr = 72000/60×60 = 20m/s

final velocity = 0

time = 45seconds

v = u + at

0 = 20 - 45a

a = 20/45 = 0.44444 m/s^2

retardation = 0.4444 m/s^2

acceleration = -0.4444 m/s^2

Answer 2

Given:

☛ velocity, u = 72 km/h

or u = 20 m/s

☛ time, t = 45 seconds

☛ final velocity, v = 0m/s because The car stops.

To Find:

☛ retardation = ??

Solution:

We know,

☛ v = u + at

☛ 0 = 20 + a×45

☛ 45a = - 20

☛ a = -20/45

☛ a = - 0.44

Hence, Retardation will be 0.44 m/s²