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: Physics question-finding the magnitude of the electric field

  1. Dec 27, 2008 #1
    Physics question--finding the magnitude of the electric field

    1. The problem statement, all variables and given/known data
    A charged insulating ball of mass 7.0g with a uniform charge of 1.5mC hangs from a light thread inclined at an angle of 8 degrees to the vertical. Calculate the magnitude of the electric field.

    2. Relevant equations

    e= Fe/q

    3. The attempt at a solution
    I tried to use e=mg/q and i kept getting the wrong answer. Im not sure how or if i should use the given angle.Im confused because i dont know which formula i need to use for this question.
    Last edited: Dec 27, 2008
  2. jcsd
  3. Dec 27, 2008 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Re: Physics question--finding the magnitude of the electric field

    That would apply if the ball were suspended solely by the electric field, but its not--there's a string attached.
    Which way does the field point? (I presume horizontally.)

    What forces act on the ball? (Draw a diagram for yourself.) What must the net force be? Hint: Consider vertical and horizontal force components separately.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook