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Homework Help: Is the upward Ff of a stationary block on an incline more or less than mg?

  1. Jan 11, 2012 #1
    A block of mass m remains at rest on an incline. The force acting up the ramp on this block is
    a. 0
    b. mg
    c. less than mg
    d. more than mg

    I understand that the force of friction cannot be more than the force of gravity because it would then move upward... but how is that the force of friction is less than (mg)? Wouldn't the block then slide down?

    Of course it wouldn't because of the mgsin(x)... but I just need some clarification more than anything. Trouble to grasp for some reason.
  2. jcsd
  3. Jan 11, 2012 #2


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    Hello mirandab17 . Welcome to PF !

    A component of the normal force is vertical, so ...
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