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Homework Help: Static equilibrium, diving board

  1. Mar 3, 2010 #1
    1. The problem statement, all variables and given/known data
    A person who weighs 620 N stands at x = 5.00 m, right on the end of a long horizontal diving board that weighs 350 N. The diving board is held up by two supports, one at its left end at x = 0, and one at the point x = 2.00 m. (a) What is the force exerted on the support at x = 0? (b) What is the force acting on the other support? (Use positive to indicate an upward force, negative for a downward force.)

    2. Relevant equations
    sum T=0, T=FR
    Mgp=wieght of the person
    Mgb=weight of the board
    FA=force at point a - the left most support
    FB=Force at point b - the rightmost support

    3. The attempt at a solution
    I dont know what im doing wrong, but apparently these answers are incorrect.
    (a) sum T= 0 =-Mgp*Rp+(-Mgb)*Rb+FA*Ra
    all about point b
    about point a
  2. jcsd
  3. Mar 3, 2010 #2


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    Science Advisor
    Homework Helper
    Gold Member

    Your numbers are OK (might want to round them off), but read the question carefully. It asks for the force on the supports, not the force of the supports on the diving board (think of Newton 3).
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