1. The problem statement, all variables and given/known data Refer to the figure below. Find the magnitude of the electric field if the string with a 7 gram ball carrying a charge of 4 x 10-9 C forms an angle of 35o with the vertical. http://www.montereyinstitute.org/courses/AP%20Physics%20B%20II/course%20files/assignments/lesson31selfcheckquiz_files/image001.gif a. 1.41 x 106 N/C b. 1.20 x 107 N/C c. 2.30 x 107 N/C d. 6.25 x 108 N/C 2. Relevant equations Fg=mg E=F/q 3. The attempt at a solution Force due to electric field=Force due to gravity: F=mgcos(θ) F=7*10^-3kg*9.81m/s^2*cos(35) F=Eq E=F/q E=(7*10^-3kg*9.81m/s^2*cos(35))/(4x10^-9)C E=1.41x10^7 N/C which is not an answer...the correct answer in the key is b, but I dont know why?