A car (1396 kg) collides with a truck (2175 kg) head on at the intersection of 114th and University Avenue, an intersection that is proof that civil engineers need more training. The wreckage sticks together. The car is initially travelling at 23.1 m/s and the truck is travelling at 17.0 m/s. How much kinetic energy is lost in the collision? Express your answer as a positive number of Joules.