Momentum physics

Question

A small car is sitting in a parking lot. Unfortunately, a large truck is moving too fast, and accidentally crashed into the small car. They stick together and continue moving immediately after the crash. Assume that the engine of the truck dies just before the crash, and that the trucks brakes also failed. Select all that are true for what happened just before the crash to immediately after the crash.

velocity of the car increased or decreased

velocity of the truck increased or decreased

momentum of the car increase or decreased

momentum of the truck increased or decreased

momentum or car+truck increased, decreased, or stayed the same.

Answer 1

Momentum is essentially the amount of motion an object has.

velocity of the car increased (since it wasn't moving prior to being hit, and now it is)

velocity of the truck decreased (since it is now stuck to something else, and becomes a "larger" object that still has to move with that same input of motion)

momentum of the car increase

momentum of the truck decreased

momentum or car+truck stayed the same (momentum is conserved, hence why one object increases in motion, and the other decreases in motion)