A ball rolling down a hill transfers gravitational potential energy into kinetic energy with 80% efficiency. If it starts from rest and it’s elevation changes by 6 meters, find the increase in its speed

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.