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Homework Help: Centripetal Force

  1. Jun 25, 2010 #1
    A highway curves to the left with radius of
    curvature R = 46 m. The highway’s surface
    is banked at θ = 26 so that the cars can take
    this curve at higher speeds.
    Consider a car of mass 1018 kg whose
    tires have static friction coefficient µ = 0.57
    against the pavement.
    The acceleration of gravity is 9.8 m/s/s.

    Ho fast can the car take this curve without skidding to the outside of the curve?
    Answer in units of m/s.

    Here is a link for the picture: https://quest.cns.utexas.edu/student/assignments/problem_pdf?courseuserassignment=10797960

    It is question #4.

    I tried to do this by setting the equations for Normal Force and Frictional Force equal and solving for V.
    Therefore I got,

    { (v2/R)cos(theta) - mgsin(theta) } = { u (v2/R)*sin(theta) + mgsin (theta))

    However, I am unable to get the correct answer.

    Help is needed as soon as possible. Thank you.
     
  2. jcsd
  3. Jun 25, 2010 #2

    The diagram to not show up.

    Is it possible for you to draw a free body diagram showing the forces on the car so we might be able to work through the equations you will need based on the diagram?
     
  4. Jun 25, 2010 #3
    The link asks for a login.
     
  5. Jun 25, 2010 #4

    ehild

    User Avatar
    Homework Helper

    Why should be the normal force equal to the frictional force?
    You mix acceleration and force in your equation. How did you get it?

    ehild
     
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