Physics question-finding the magnitude of the electric field

  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
    q=mg/e

    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. Doc Al

    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.
     
Know someone interested in this topic? Share a link to this question via email, Google+, Twitter, or Facebook