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Homework Help: Static problem Help

  1. Nov 28, 2008 #1
    static problem..plz Help

    1. The problem statement, all variables and given/known data

    a horizontal bar that is sticking straight out from the side of a building has a cable attached at its end. if the tension in the cable is 2400 N when it is supporting a sign that weighs 300N, what force is the bar exerting on the sign and what is the angle between the cable and the building

    2. Relevant equations

    a2 + b2 = c2
    cos theta= adj/hyp
    sin theta= opp/hyp
    tan theta= opp/adj

    3. The attempt at a solution

    for the force of the bar exerting on the sign I have 2381.18N by using the a2 + b2= c2 equation.
    I'm not sure which degree angle is it really asking for in my diagram. I think its the 82.82 degrees.
    I know one of the degrees is a right angle, which is 90 degrees.
    However, for the second question is my answer correct?? or is it askin for the other degrees?? which is 7.2 degrees.

    Thank you for all help!!
  2. jcsd
  3. Nov 29, 2008 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Re: static problem..plz Help

    Yep, looks good; it is asking for the angle between the cable and building, which is the 82.8 degrees. Draw a quick sketch; the 7.2 degrees is the angle between the cable and bar.
  4. Nov 29, 2008 #3
    Re: static problem..plz Help

    thank you thank you
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