Question

Two passenger cars, car A and car B, of the same weight are put to a 30 mph head-on crash test. In the test, cars are pulled forward by a cable at 30 mph speed into a flat concrete wall. After the crash test, the length of the cars became shorter because the frontal part of the cars got crumbled at the crash. If car A’s length got shortened much more than car B’s,
(A) the impact force on car A was much less than on car B during the collision.
(B) the impulse on the car A was much more than on car B during the collision.
(C) the impulse on the car A was much less than on car B during the collision.
(D) the impact force on car A was much more than on car B during the collision.

the statements the correct one is A

Explanation:

Let’s analyze this exercise, vehicles have the same mass and speed, so we can use the momentum impulse ratio

I = ∫ F dt = Δp

the Δp is the same for both cars since they have the same mass and the same speeds, so the momentum is the same in both vehicles

When they indicate that vehicle A was reduced more than vehicle B, this implies that the force acted for a longer time, to have the largest reduction in size, therefore the impact force was less in car A than in car B

Resisting the statements the correct one is A