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Homework Help: Cart rolling down hill

  1. Mar 10, 2010 #1
    1. The problem statement, all variables and given/known data
    An 0.80-kg cart rolls down a 30.0° hill from a
    vertical height of 0.50 m. The distance that the cart must roll to the bottom of
    the hill is 0.50 m/sin 30.0°=1.0 m. The surface of
    the hill exerts a frictional force of 5.0 N on the cart.
    Does the cart roll to the bottom of the hill?


    2. Relevant equations
    I do know what equation to use or how to get the problem started.
    f=ma


    3. The attempt at a solution
    F=9.8m/s^2(.8kg)
    F=7.84N(sin30)
    F=3.92N
    so it doesn't over come the frictional force.
     
    Last edited: Mar 10, 2010
  2. jcsd
  3. Mar 11, 2010 #2

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    Welcome to PF!

    Hi rawr8712! Welcome to PF! :smile:

    Yes, the downhill component of gravity is 3.92N, so if the friction force is 5N, the cart will accelerate uphill!!. :rolleyes:

    Are you sure you've copied the question accurately?​
     
  4. Apr 11, 2010 #3
    Re: Welcome to PF!

    the cart will not accelerate up the hill seeing as the force stated for friction is the maximum force that friction can exert not a constant. therefore the cart will not move
     
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