What is the Charge on the Styrofoam Ball in an Electric Field Experiment?

[jonno426]

Homework Statement

In an experiment you find that a small styrofoam ball of mass m can be suspended in mid-air by an electric field of magnitude c pointing straight downward, towards the earth.

Its looking for the charge on the styrofoam ball, and I have no equation to help me solve for it.

Homework Equations

Lol that's what I'm lookin for.

The Attempt at a Solution

 

[Hootenanny]

What is the equation for the force experienced by a charge q in an electric field E?

 

[jonno426]

k(q1)(q2) / l^2?

 

[ranger]

k(q1)(q2) / l^2?

You are given the magnitude of the E field. Note that much emphasis was placed on q and E. The force is proportional to product of two things...