6. a skier starts from rest at the top of a frictionless incline of height 20.0 m. at
of the incline , the skier encounters a horizontal surface where the coefficient of
friction between skis and snow is 0.210.
a. find the skier's speed at the bottom.
b. how far does the skier travel on the horizontal surface before coming to rest?
(neglect air resistance)

6. write an energy problem.