A car of mass 2200 kg collides with a truck of mass 4500 kg, and just after the collision the car and truck slide along, stuck together, with no rotation. The car's velocity just before the collision was < 35, 0, 0 > m/s, and the truck's velocity just before the collision was < -18, 0, 27 > m/s.
The Attempt at a Solution
I attempted to use the change in kinetic energy of the system to solve of the change in internal energy.
Ef=.5*6700*<-.597,0,18.134>2 <-- final velocity of the system was calculated in an earlier step and found to be correct
I then found the change in energy by Ef,sys-Ei,sys and then getting the magnitude to solve get change in internal energy. This however did not get me the correct answer. I am stuck and not sure what to try.