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Homework Help: Three children slide down a hill.

  1. Oct 4, 2012 #1
    Three children, Aaron (20kg), Beth (25kg) and Charlie (30kg) take off on sleds at the top of a hill. Who will reach the bottom first? (μ=.15)
    d)All of them reach at the same time


    The answer is d. my first guess was A because i thought that since Aaron had the lowest mass his weight force, and therefore his normal force, would be the smallest; giving him the least amount of resistive frictional force. Why is d correct?
  2. jcsd
  3. Oct 4, 2012 #2
    Find the net force on the body.
    Then you can find the acceleration for any mass.
  4. Oct 4, 2012 #3
    but how would I do that if i don't know the [itex]\theta[/itex] of the hill? I drew out my free body diagram but i keep getting stuck when try to resolve the components of the forces.
  5. Oct 4, 2012 #4
    Just put θ as constant for all the cases.
  6. Oct 4, 2012 #5
    :approve:Got it thanks
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