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Homework Help: Friction problems

  1. Feb 14, 2010 #1
    1. The problem statement, all variables and given/known data
    A child rides on a toboggan down a frictionless hill, at 31.0o with respect to the horizontal. The combined mass is 75kg. They are one system.
    a) Clear Free Body Diagram
    b) Find Acceleration
    c) If the mass increases does the acceleration increase, decrease, or stay the same?
    3) There is a 35kg box being pulled up an incline of 30o at a velocity of 6.7m/s with a tension of 350N. The μk = .27.
    a) Clear Free Body Diagram
    b) Find Acceleration
    4) There is a 60kg box going down an incline of 35o with an acceleration of 4.00m/s2 but it is being pulled on by a tension of 400N.
    a) Clear Free Body Diagram
    b) Find μk
    5) There is a 1110kg car rounding a corner with a radius of 30m. The μs = .45.
    a) Clear Free Body Diagram
    b) Find Velocity.
    6) There is a 1250 kg car rounds a banked road of 60o with a 40m radius at a velocity of 6m/s.
    a) Clear Free Body Diargram
    b) Calculate FN

    2. Relevant equations

    3. The attempt at a solution

    im not sure how to approach these type of problems. the free body diagrams arent that bad for me but still poses a bit of a problem. any help would be appreciated.
  2. jcsd
  3. Feb 14, 2010 #2


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    Science Advisor
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    Gold Member

    Drawing good free body diagrams and then applying Newton's laws are essential in solving these type of problems. Why don't you try the first one and then someone can give you some help.
  4. Feb 15, 2010 #3
    please show us your solution and indicate where exactly you have problem so we can help :) ..
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