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: Equilibrium of systems in acccelerating frame

  1. May 5, 2013 #1
    69g5g8.png

    I've drawn the following FBD (using D'alembert prinicple)
    [The N in my drawing is the F_A stated in the question]

    579kn.jpg
    ----------------

    Assuming my FBD has nothing wrong, am I right to say that I am free to choose my torque equation about ANY POINT?

    somehow my solutions vary depending on my point of consideration.

    Torque eq about CM:
    N + 2Fy cos(30) -2Fx sin(30) = 0

    -or-
    or eq about pivot:
    N - 2mg cos(30) - 2ma sin(30) = ma

    It just doesnt give the same solution.
    --------------------------------------------
    My other translational equilibrium eqs are:

    ma - Nsin(30) + Fx = 0
    Fy + Ncos(30) - mg = 0
     
  2. jcsd
  3. May 5, 2013 #2
    solved.

    my mistakes when pressing the calculator )=
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted