Question

Complete the sentences below correctly. Stunt Car A and Stunt Car B are identical cars with the same mass of 48.9 kg. They are both traveling at 82.5 m/s. Stunt Car A crashes into a brick wall, while Stunt Car B crashes into a big pile of leaves. They both come to a complete stop after the impact. Stunt Car A experiences a _____________________ over a _____________ of time. Stunt Car B experiences a _____________________ over a _____________ of time. Because of the force experienced by Stunt Car A, it will sustain ____________ damage than Stunt Car B.

The possible answers are: short period, large force, more, long period, small force, less.

Answer 1

Stunt Car A experiences a large force over a short period of time. Stunt Car B experiences a small force over a long period of time. Because of the force experienced by Stunt Car A, it will sustain more damage than Stunt Car B.

Step-by-step explanation:

Both cars have the same mass and velocity, therefore they have the same momentum. During the collision, the total momentum of the car A and brick wall is conserved as well as the total momentum of the car B and the pile of leaves.

However, if we are to investigate the damage on each car, we should look at the cars not the whole system. So, the momentum difference between the cars gives us the impulse that the car felt.

`\vec{J} = \Delta \vec{P}\\\vec{F}\Delta t = \vec{P}_2 - \vec{P}_1`

Since the Car A will crash the wall quicker than the other car crashes through the pile of leaves,

`\Delta t_1 < \Delta t_2`

which gives us

`F_1 > F_2`