Question

A car moving along a straight highway with a speed of 72km/h is brought to rest within a distance of 100m. Whats is the retardation of the car and how long does it take for the car to shop?

Answer 1

Hey buddy! Here's your answer!

u = 72 km/h = 72*5/18 = 20 m/s

s = 100 m

v = 0 m/s

v^2 = u^2 + 2as

0 = 400 + 200a

a = -2 m/s^2

t = (v - u)/a

 = (0 - 100)/-2

t  = 50 s

Retardation is 2 m/s^2 and time taken is 50 s.

Hope this helps! :)