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Homework Help: Banked Highway Curve Question

  1. Oct 13, 2007 #1
    Hey, I'm really having problems with this question and I don't really know what to do. I'm hoping someone can help me. Thanks in advance.

    1. The problem statement, all variables and given/known data
    A highway curves to the left with radius of curvature R = 35 m. The highway's surface is banked at 19 degrees so that the cars can take this curve at higher speeds.
    Consider a car of mass 907 kg whose tires have static fiction coefficient of .72 against the pavement.
    The acceleration of gravity is 9.8 m/s^2.

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

    2. Relevant equations
    (mv^2)/r = Fn Sin(angle)
    mg = Fn Cos (angle)
    (v^2)/rg = Tan (angle)
    Ac = g tan (angle)
  2. jcsd
  3. Oct 14, 2007 #2


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    Staff Emeritus
    Science Advisor

    Please show some effort and work.

    Consider friction also. Ffriction = [itex]\mu[/itex]Fn

    To keep the car on the road, the weight component pointing down the curve and the friction must be equal to the inertial force of the car mv2/r.

    On a bank/ramp, the weight can be resolved into normal and parallel forces with respect to the plane of the road.

  4. Oct 14, 2007 #3
    Alright, thanks. I already knew that stuff.

    The question was killed anyway, so I don't have to do it. Thanks for your help.
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