A 62.0 kg skier is moving at 6.80 m/s on a frictionless, horizontal, snow-covered plateau when she encounters a rough patch 4.80 m long. The coefficient of kinetic friction between this patch and her skis is 0.300. After crossing the rough patch and returning to the friction-free snow, she skis down an icy, frictionless hill 2.50 m high.
(a) How fast is the skier moving when she gets to the bottom of the hill?
(b) How much internal energy was generated in crossing the rough patch?
