Energy transfer, not sure how to do

[GunarsA]

Homework Statement

1) 27,000 kg railroad car moving at 2.7 m/s hits a railroad car (stationary) weighing 9,300 kg. Heavy railroad car goes opposite direction at .6 m/s. How fast will the empty car go?

Homework Equations

no clue

The Attempt at a Solution

No idea where to start with this

 

[cupid.callin]

Hi GunarsA

Welcome to PF !

did you try Using conservation of momentum??​

 

[Sniperman724]

This sound like a coughinelasticcollisioncough problem :)