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: Torques on a Rod - Need Quick Help!

  1. Nov 30, 2011 #1

    If anyone can give me some quick help on this, I would appreciate it.

    Thanks in advance.
  2. jcsd
  3. Nov 30, 2011 #2
    I can't quite tell, but it looks like it's possible that the vertical and horizontal components of force could each sum to zero. But what about the moments? Try computing the sum of the moments about the center of the rod. Is it zero?

  4. Dec 1, 2011 #3
    Well, looking at the horizontal axis only we can assume from the picture that the rod is in translational equilibrium (it doesn't move) along the horizontal axis. But looking in the vertical axis, we see a greater force downwards than the vertical component of F(3), so the rod is actually moving downwards (it's not in vertical translational equilibrium). Even if we assume that the rod is in translational equilibrium both in horizontal and vertical axes due to diagram error, if you call your pivot point the point where F(2) is acting upon, the only torque applied is a counterclockwise torque by the vertical component of F(3), which is perpendicular to a radius extending from the rod = actual torque.

    I hope that helps!
  5. Dec 1, 2011 #4
    Thanks guys! I appreciate the help!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook