Question

The mass of a car along with its rider is 1000kg. It is moving with a velocity of 72km/hr and takes 5 second to stop after the brakes are applied .Calculate the retardation and retarding force exerted by the brakes on the car.

Answer 1

Answer:

Explanation:

m=1000kg

u=72km/h=72×5/18=20m/s

V=0m/s

t=5s

a=? and f=?

Use, Newton's first law of motion:-

•V=u+at (retardation)

0=20+5a

a= -4m/s^2

•retardation exerted by the brakes on the car is 4m/s^2

• Force= mass × acceleration

F= m × a

F =1000× -4

F= -4000N

• retarding force exerted by the brakes on the car is 4000N