Anonymous
Anonymous asked in Science & MathematicsPhysics · 1 month ago

need help with physics 11 question?

Drag race tires on asphalt have a very high coefficient of friction. If a race car finishes a quarter-mile (402m) in 6.0s, what is the coefficient of static friction? (Assume the tires don't slide, the car accelerates uniformly, no air resistance).

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  • 1 month ago

    The coefficient of friction is the horizontal ( friction ) force / normal reaction.  = ma / mg = a/g

    the acceleration can be found from s= 1/2 a t^2 -> a = 2s/ (t^2)

    -> coefficient = (2s/(t^2)) / g = 2*402/(6^2 * 9.8) =  2.28 +-  0.01

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  • 1 month ago

    d = ½at²

    a = 2d/t² = 804/36 = 22.3 m/s²

    F = ma = 22.3m 

    w = mg = 9.8m

    μ = force of friction/weight = 22.3/9.8 = 2.28

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