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Rolling car down a hill

  1. Nov 30, 2008 #1
    1. The problem statement, all variables and given/known data
    A toy car has a total mass of 50 g, and rolls on freely spinning wheels, each of which can be modeled as a uniform disk of mass 1 g, and radius 2mm. What is the acceleration, a, of this toy car when it rolls without slipping down a ramp tilted at an angle of 20 degrees to the horizontal? By what factor is the toy car faster or slower than a frictionless block of the same total mass, ie what is a_car/a_frictionless?

    2. Relevant equations
    velocity_center of mass=wr (w is angular velocity, r is radius)

    3. The attempt at a solution
    I don't know how to start this....how do you find the acceleration?
  2. jcsd
  3. Nov 30, 2008 #2
    This is like IPhO 2002 problem #3, I don't get it... maybe the solution for it will help?

    http://www.jyu.fi/kastdk/olympiads/ [Broken]
    Last edited by a moderator: May 3, 2017
  4. Nov 30, 2008 #3
    I don't see a link for the solution for that problem on the site you posted...I see the question, though. Can you send me a link to the solution?
  5. Nov 30, 2008 #4
    hmm there's no link, I got there by going to the homepage then press on IPhO 02 and then the questions on the top with the answers on the bottom

    I got to the part with 5 equations and 5 unknows but I haven't solved it yet. it seems like just a bit more complex situtation of your problem.
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