What is the angle of the car-truck combination after an inelastic collision?

[mrshappy0]

Homework Statement

A blue car with mass mc = 499 kg is moving east with a speed of vc = 21 m/s and collides with a purple truck with mass mt = 1283 kg that is moving south with a speed of vt = 11 m/s . The two collide and lock together after the collision.

What is the angle that the car-truck combination travel after the collision? (give your answer as an angle South of East)

Homework Equations

(1/2)mv^2

The Attempt at a Solution

I am not really sure how to set this problem up. I understand that they will stick together and that the momentum will be conserved. I also understand that this problem will require breaking it down into move along the x and y-axis but how do start.

 

[mrshappy0]

along x:
mass of truck (velocity) +mass of car(velocity)=(mass of truck and car)(vx)
. solve..

along y:
mass of truck (velocity) +mass of car(velocity)=(mass of truck and car)(vy)

ArcTan[x/y]=...

Love answering my own questions.