KEY PROBLEM (not from text) ----------An 80 kg ...

KEY PROBLEM (not from text) ----------An 80 kg skier starts down a flat slope that makes a 16 degree angle, with respect to the horizontal. If the skier began at an altitude of 4500 ft. and the coefficient of kinetic friction = 0.18, at what speed is the skier moving at an altitude of 4100 ft.?

Answers ( 1 )

  1. esther byrd
    esther byrd
    Using the work energy principle we have
                    -Wnc = DK.E. +D P.E.
                   -µkmgdCos16 = 1/2 ( vf2-vi2 ) + mg ( h2-h1)
                   -µkmgCos16 *400/Sin16 =1/2  vf2  + mg (-400)
                                         vf2 =400*9.8*30.5*10-2 (80 - 0.18tan16 )
    simplifying we get  vf =12.6m/s   

                  

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