1. The problem statement, all variables and given/known data http://aycu16.webshots.com/image/13135/2004772066267823450_rs.jpg The mass of the ball is 40 milligrams, the applied potential difference is 480 V and the plate separation is 6 cm. If the string hangs at an angle of 20deg to the vertical, determine the charge on the pith ball. 2. Relevant equations E = V / d E = F / q 3. The attempt at a solution I figured first i should use E = v/d so i did E = 480/0.06 = 8000 Then i found F using trig and vectors Cos20 = (40*10^-6) / F Thus F = 4.26*10^-4 N Then i plugged in my F and E into the equation q = F / E q = 4.26*10^-4 N / 8000 = 5.3*10^-9 C Which is 5.3 nC But the correct answer is supposed to be 18nC Forever grateful for assistance.