At a carnival, some students are riding bumper cars. A 100 kg bumper car gliding at 1.6 m/s bumps into a 120 kg bumper car

that is at rest. If they collide elastically and the 120 kg car has a velocity after collision of 1.45 m/s,

what is the final velocity of the 100 kg car after they bounce apart?

To practice problem-solving strategy 10.1 for energy conservation problems. a sled is being held at rest on a slope that makes an angle θ with the horizontal. after the sled is released, it slides a distance d1 down the slope and then covers the distance d2 along the horizontal terrain before stopping. find the coefficient of kinetic friction μk between the sled and the ground, assuming that it is constant throughout the trip.