A compact car and a large truck collide head

Question

on and stick together.
Which undergoes the larger change in the
magnitude of momentum?

1. Can’t tell without knowing the final velocity of the combined mass.
2. truck
3. car
4. The momentum change is the same for
both vehicles.

Answer 1

The correct answer is:

4. The momentum change is the same for both vehicles.

In a collision where two objects stick together, the law of conservation of momentum applies. According to this law, the total momentum before the collision must equal the total momentum after the collision. Therefore, both the compact car and the large truck undergo an equal change in momentum in magnitude but in opposite directions.

While the absolute value of the momentum changes might be different (since they may have different initial momenta due to their different masses and velocities), the change in momentum experienced by each vehicle is equal in magnitude but opposite in direction, leading to the conclusion that both undergo the same change in momentum magnitude.