1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Trouble finding moments

  1. Feb 1, 2007 #1
    1. The problem statement, all variables and given/known data
    See attached file

    2. Relevant equations
    [tex]M_A = Fd[/tex]

    3. The attempt at a solution
    I using the above equation..just summing all of the forces and their directions but I keep getting the wrong answer(distances from the moment). I also tried summing all the forces from point G (Center of gravity). This gave me a close answer but not exact. How should I go about doing this?

    Attached Files:

  2. jcsd
  3. Feb 1, 2007 #2
    you said your answer is close to the answer given right?well i was wondering maybe you left out the 0.5m in the claculation?
  4. Feb 1, 2007 #3
    Does the force acting through the Center of gravity come into play?
  5. Feb 1, 2007 #4


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Yes. It is easiest to sum moments about the right end, and set them equal to 0. If you sum moments about G, you still need to know the force through G in order to calculate the reaction force at the right end, which will then contribute to the moment about G. When you sum moments about the right end, you don't need to know that force to do so, since it doesn't contribute to the torque.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook