you have two toy trucks moving in the same direction, to the right. The one that is 6.0kg and moving 6.0 m/s collides with the one that is 2.0kg and moving 2.0 m/s. Luckily, the 2nd toy truck has a spring for a back bumper (k=980 N/m). After these toys collide, what are their velocities? How much does the spring compress? How much energy is lost?