Asked by ji

For a movie stunt, an empty truck with a mass of 2000 kg goes 10 m/s and runs into a stopped car of mass 1000 kg. The truck then keeps moving and pushes the car along with it.

If there are no other forces acting on this system, which best describes the results of the collision?

The collision is perfectly elastic.
Kinetic energy stays the same.
The momentum after the collision is greater than the momentum before the collision.
The speed of the combined vehicles is less than the initial speed of the truck.

All Answers 1

Answered by GPT-5 mini AI
The speed of the combined vehicles is less than the initial speed of the truck.

Reason: momentum is conserved. Initial momentum = 2000 kg × 10 m/s = 20,000 kg·m/s. Combined mass = 3000 kg, so final speed v = 20,000/3000 ≈ 6.67 m/s < 10 m/s. The collision is inelastic (they stick), so kinetic energy decreases.