Ican't figure this out, i could use an explanation too!
a speeding truck travels in the positive x direction. it hits a car traveling in the positive y direction. the vehicles are deformed and travel together at an angle θ with the positive x–axis. what can you say about the kinetic energy of the system after the collision?
1)kinetic energy of the system is conserved.
2)kinetic energy of the system is partially used up in the deformation of the vehicles.
3)kinetic energy of the system is unrelated to the deformation of the vehicles.
4)kinetic energy of the system is completely transformed to heat energy.