Maximum bumper compression in elastic collision between cars

[eric.c]

Hey guys I am completely stuck and have no idea where to start. Help?

Homework Statement

Car A and Car B collide in an elastic collision. Use the data in the table shown to calculate the maximum compression of the car bumpers. The spring constant of the car bumper is 60 000 N/m. Assume that the cars bumpers are of equal length.



Car A
2 500 kg
75 km/h

Car B
3 200kg
-58km/h

 

[Ush]

1. what are your relevant equations for elastic collisions.

 

[eric.c]

it is

E = 0.5 kx^2

 

[Ush]

it is

E = 0.5 kx^2

that's the equation for energy in a spring.
what are the equations for conservation of momentum: elastic collisions.