Question

A compact car, mass 660 kg, is moving at 1.00 ✕ 102 km/h toward the east. The driver of the compact car suddenly applies the brakes hard for 2.1 s. As a result, an average force of 4.8 ✕ 103 N is exerted on the car to slow it down. (a) What is the change in momentum, that is the magnitude and direction of the impulse on the car?

Answer 1

-10,080N/s

Step-by-step explanation:

Change in momentum = Force × time

Given : F = 4.8 × 10^3N

Time,t = 2.1seconds

Change in momentum = (4.8×10^3)×2.1 =-

-1 0,080N/s

The negative sign shows that the force is opposite the direction of the velocity.

Answer 2

Answer:
`59.43* 10^3 kg-m/s`

Step-by-step explanation:

Given

mass of car
`m=660 kg`

Initial velocity of car
`=102 km/h\approx 28.33 m/s` towards east

Time taken to stop
`t=2.1 s`

Force exerted
`F_(avg)=4.8* 10^3 N`

change in momentum is given by impulse imparted to the car

`Impulse(J)=-F\cdot t`

`J=-4.8* 10^3* 2.1`

`J=-59.49* 10^3 kg-m/s`

negative Sign indicates that impulse is imparted opposite to the direction of motion

magnitude of momentum
`J=59.49* 10^3`