Finding kinetic energy consevered after collision

[qwerty5050]

Homework Statement

2 cars of equal mass and traveling in opposite directions on a wet and slippery road collide and lock together after impact. Neither car brakes before the collision. The tangled wreck moves off in an easterly direction at 5 m/s immediately after the collision. if one car was traveling due west at 20 m/s immediately before the collision and the other at 30 m/s.
What fraction of the initial kinetic energy as conserved during the collision?

Homework Equations

Ek=1/2mv^2 - this is the only equation i know that has to do with kinetic energy

The Attempt at a Solution

I have no idea what i have to do

 

[gneill]

I have no idea what i have to do

Start by listing equations that you think may be relevant. Perhaps that will trigger an idea or two for an attempt.

 

[qwerty5050]

Start by listing equations that you think may be relevant. Perhaps that will trigger an idea or two for an attempt.

I've been doing that but I'm still not sure what to do.

 

[gneill]

I've been doing that but I'm still not sure what to do.

Hmm. You haven't posted any, so we can't tell if you're on the right track or not.

The topic is kinetic energy. What equations do you know pertaining to kinetic energy?

 

[Suraj M]

Try to think of things that remain constant during the given collision. Any law you know that might apply. Think!