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Homework Help: Centripetal Force: Banked Curve

  1. Oct 31, 2011 #1
    1. The problem statement, all variables and given/known data
    A 1200 kg car travels around a curve banked at 42.5 degrees in a circular path of radius = 150m, but the ramp is only 55m long. The force of friction on the car is 9000N, calculate the speed of the car.


    radius = 150 m
    θ (angle the incline makes with the horizontal) = 42.5
    mass = 1200 kg
    Friction = 9000 N

    2. Relevant equations

    Fc= FNx + FFx

    Fc= mv2 / r

    3. The attempt at a solution

    The car does not move in the y-plane, therefore:

    Ff + Fg + FN = 0

    FN = (mg + Ffsinθ)/cosθ

    Solve for FN and I got 24213.83512 N

    Then I used the value of FN to find FNx and added FFx to it.

    Then I multiplied by the radius, divided by the mass and took the square root leaving me with 54m/s.

    However, when I use the formula found on this page http://en.wikipedia.org/wiki/Banked_turn" [Broken] I got 67 m/s.

    Which one is right? And If I'm wrong, where did I go wrong?
    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Nov 1, 2011 #2
    How did you apply the 9000N to the equations on the Wiki site?
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