what is the net charge on the ball?

Question

A m=2g ball is suspended by a 1 = 20 cm long string, in a constant electric field of E=1000 N/C. If the string makes an angle of 0 = 15 degrees with respect to the vertical, what is the net charge on the ball?

Please show work

Answer 1

F=mg sin(15)
F - horizontal component of ball's weight
m - balls mass
g - acceleration due to gravity

and electric force on the ball is
Fe= Eq
E - electric field
q- ball's charge

q= Fe/E

Sum of forces = 0 that is F=Fe

so
q=F/E=mg sin(15)/E