<p>The problem appears to be from 1998 and is on pg. 13 of this doc: <a href="http://apcentral.collegeboard.com/apc/public/repository/ap05_oe_gr_physics_ha_45144.pdf%5B/url%5D">http://apcentral.collegeboard.com/apc/public/repository/ap05_oe_gr_physics_ha_45144.pdf</a></p>
<p>so far I have:</p>
<p>a. Ft (tension) drawn in the second quadrant at an angle similar to the angle the string makes with the wall, mg along the -y axis, and Fe (electric) along the +x axis</p>
<p>b. E = F/q = (.032N)/(80x10^-6C) = 400 N/C, pointing left horizontally towards the wall</p>
<p>c. not sure about this one, I have E = V/d => d = V/E, except I don't know where to begin to find the potential difference, perhaps an easier way...</p>
<p>d. i. Fnet = sqrt[(.032N)^2 + (.98N)^2] = .98 N = ma = (.01kg)a => a = 98 m/s^2, directed in 4th quadrant along Ft (tension)</p>
<p>ii. um southeast in the same direction as part d?</p>