1. Not finding help here? Sign up for a free 30min 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!

Need help setting up Eqtn of motion.

  1. Aug 15, 2005 #1
    Torque in Electric Field...need help with eqtns of motion...

    Ok - I have a charged square plate Q with a weightless rod attached through the centre of the plane so that the plate can rotate like a propeller.

    Half of the plate sits in an E field and so feels a torque.
    The E field drops off as [tex] \frac{1}{r^2} [/tex]

    I need to set up the equation of motion.

    Now, I know that:

    [tex] \Gamma = Fd [/tex]

    My problem is that [tex]F=F(\theta) \:and\: d=d(\theta) [/tex]

    i.e as the plate rotates less of it will feel the electric field - it will be completely half immersed in the E field at an angle of 0 deg (perp to field)and will feel the max force, and be at a min when the plate is parallel to the field and feel zero force.

    Also as the plate rotates some if it will be closer to the E field and some of it will be further away so there is also the theta dependant distance.

    Can anyone help me set up the eqtns of motion?
    Last edited: Aug 15, 2005
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you help with the solution or looking for help too?
Draft saved Draft deleted

Similar Discussions: Need help setting up Eqtn of motion.
  1. Help I need questions! (Replies: 0)

  2. Statics help needed! (Replies: 0)