Question

A 1500 kg car originally moving at 10 m/s crashes into a wall and comes to rest in 0.25 s. What is the magnitude of the impulse given to the car?
a. 37.5 kg m/s
b. 150 kg m/s
c. 15,000 kg m/s
d. 60,000 kg m/s

Answer 1

Answer:

Option C

Explanation:

Impulse is the change in momentum in an object hence given by

Impulse=F∆t

Impulse=∆p=m(v-u)

Here, F is force applied, t is rime, m is mass, v is final velocity and u is initial velocity

Given that the question has time but no magnitude of the force, we use the sexond equation.

Taking forward velocity as negative then u=-10 m/s, also since the car comes to rest, final velocity is 0 m/s. Substititing mass with 1500 kgs then

Impulse=1500(0--10)=15000 kg.m/s