The driver of a car applies the brakes for 4.0 s. As a result an average force of 7500N is exerted in the car to slow it down. What is the change in momentum of the car.

The change in momentum of the car is 30,000 kg m/s

Explanation:

Given,

The force exerted on the car to slow down, F = 7500 N

The time period of force, t = 4 s

The rate of change of momentum of the object is equal to the force acting on it.

Therefore,

(mv - mu) / t = F

Where v and u are the final and initial velocity of the car. The change in momentum of the car,

mv - mu = F x t

= 7500 x 4

= 30,000 kg m/s

Hence the change in momentum of the car is 30,000 kg m/s