Question

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.

Answer 1

Answer:

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