A 72.4-kg skier coasts up a snow-covered hill that makes an angle of 23.2 ° with the horizontal. The initial speed of the skier is 8.14 m/s. After coasting a distance of 1.81 m up the slope, the speed of the skier is 4.97 m/s.
(a) Find the work done by the kinetic frictional force that acts on the skis.
(b) What is the magnitude of the kinetic frictional force?