A 4.5 kg box slides down a 4.2-m -high frictionless hill,starting from rest, across a 2.3-m -wide horizontal surface, thenhits a horizontal spring with spring constant 480 N/m . The otherend of the spring is anchored against a wall. The ground under thespring is frictionless, but the 2.3-m-long horizontal surface isrough. The coefficient of kinetic friction of the box on thissurface is 0.26.
What is the speed of the box just before hitting the spring? Howfar is the spring compressed? Including the first crossing, howmany complete trips will the box make across the rough surfacebefore coming to rest?
