10. Conservation of Energy

An 800kg car skids to a stop from 30m/s through a distance of 90m. Calculate the coefficient of friction between the car and the road.

(I) You drop a basketball from a height of 5.0 m, which rebounds to a new height of 3.0 m. How much energy is lost to nonconservative forces? Give your answer as percentage of the initial energy.

(III) A skier of mass m starts from rest at the top of a solid sphere of radius r and slides down its frictionless surface.

(b) If friction is present, does the skier fly off at a greater or lesser angle? <IMAGE>

(II) You slide down an 8.0-m-high icy hill (≈ frictionless). At the bottom is a level stretch where the coefficient of kinetic friction is 0.30. How far would you travel across the level stretch?