Physics
posted by Jen on .
A 9600 kg boxcar traveling at 17 m/s strikes a second boxcar at rest. The two stick together and move off with a speed of 9.0 m/s. What is the mass of the second car?
I know that this is an inelastic collision because the 2 stick together but I need help PLEASE!!

conservation of momentum:
9600*17+m*0=(m+9600)9
solve for m.