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## Homework Statement

A small plastic ball of mass 5.54 x 10-3 kg and charge +0.174C is suspended from an insulating thread and hangs between the plates of a capacitor (see the drawing). The ball is in equilibrium, with the thread making an angle of 30.0o with respect to the vertical. The area of each plate is 0.02030 m^2. What is the magnitude of the charge on each plate?

## Homework Equations

Electric Field = Force/test charge Electric field in plate capacitor is sigma/permitivity of space

## The Attempt at a Solution

So....

Tsin30 = mgcos30 becuz in equilibrium

T = 0.0940 which the Force then divide that by test charge gives you the electric field in that area (plate capacitor).

that quotient = charge on plate/epsilon naught * (area of plate) = my answer but its not right. Acutal answer is 3.24 x 10^-8 C