A boxcar of mass 3.21 x 10^4 kg is rolling south at 5.16 m/s when it collides and couples with another boxcar of mass 5.18 x 10^4 kg that is rolling north at 2.38 m/s. What is the velocity of the coupled boxcars after collision? Take north as positive and express your result to three significant digits.
Please I am so confused and my textbook has nothing like this to go off of.
Cons of momentum. Inelastic collision.
(3.21e4*-5.16) + (5.18e4*2.38) = (3.21e4 + 5.18e4)vf