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: Potential energy problem , i need help !

  1. Oct 22, 2006 #1
    hello !
    i have an assignment on Electric Potential Energy , can any one help me on solving it ?
    the problem says : A small sphere with mass 2.70 g hangs by a thread between two large parallel vertical plates 5.00 cm apart.
    The plates are insulating and have uniform surface charge densities . The charge on the sphere is q = 8.80×10^−6 C .
    What potential difference between the plates will cause the thread to assume an angle of 30.0 with the vertical ?
    see the figure :P

    Attached Files:

    Last edited: Oct 22, 2006
  2. jcsd
  3. Oct 22, 2006 #2
    draw the FBD of the sphere and resolve the forces in the x and y direction
  4. Oct 22, 2006 #3
    thanx ,, i think i got the answer by drawing the diagram :
    E = Mgtan(30)
    V= E.d
    it is right ?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook