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Frictional force disc brake

  1. Mar 22, 2010 #1
    I've been trying to figure out the friction coefficient of some brake pads. My test fixture only allows me to pull (F2) a brake disc between two brake pads clamped around the disc with a force F1. I then measure with a load cell the maximum force required for the brake disc to slip.

    My question is simply, will the basic equation F=UxN be valid, or is it correct to assume that F= 2x(UN) in this scenario assuming F1 and U is identical for both brake pads?

    I've been googling the topic and my impression is that both equations are used.

    Attached Files:

  2. jcsd
  3. Mar 22, 2010 #2


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    Homework Helper

    Should be F=2 x (UN). Imagine replacing one of the pads with a frictionless pad and then you'd get F = 1 x (UN) for the one pad with friction.
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