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Homework Help: Forces - time to stop

  1. Apr 8, 2007 #1
    The Question
    A skier on a slope inclined at 4.7 degrees to the horizontal pushes on ski poles and starts down the slope. The initial speed is 2.7m/s. The coefficient of kinetic friction between skies and snow is 0.11. Determine how far the skier will slide before coming to rest.

    So far i had done the following, but i am unsure if this is the right way to go about this and also what to do next to find the answer.

    in the perpendicular
    0 = mgcos4.7 [D] + Fn
    Fn = mgcos4.7

    Ff = 0.11(mgcos4.7)

    Fnet = Ff + Fgperp + fapp
    0 = mgsin4.7 - 0.11(mgcos4.7) - Fapp
    Fapp = 0.27(m)
  2. jcsd
  3. Apr 8, 2007 #2
    Little bit confused, where does it say a force is applied by the skiier to help stop.

    if no effort, along incline ma=mg(sin 4.7)-mg(cos(4.7))*.11

    If cos(4.7)*0.11 is greater than sin(4.7), skiier will slow without any effort.

    One could use that number a, to compute a and relation

  4. Apr 8, 2007 #3
    Of course - I had forgotton that equation - thank you
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