A single 1,000 kg train car moving at 3.0 m/s collides with the back of two 1,000 kg train cars linked together. It latches onto the car it strikes as the two parts of the coupled cars exert forces on each other. What is the speed of the cars immediately afterward?

What formula would I use for this problem?

Question

A single 1,000 kg train car moving at 3.0 m/s collides with the back of two 1,000 kg train cars linked together. It latches onto the car it strikes as the two parts of the coupled cars exert forces on each other. What is the speed of the cars immediately afterward?

What formula would I use for this problem?

jamesj · Answer

This is an inelastic collision. The only thing conserved is not energy but momentum.

So calculate the momentum before and after the collision.

anonymous · Answer

Okay, thank you.