given:
E= 100,000i N/C
to find:
the charge on the ball
solution:
Using force balance on mass in vertical direction
T= tension in rope
in x-direction
Fx= T*sin A= q*E
in y-direction
Fy = T*cos A = m*g
divide both equation
tan A = q*E/(m*g)
q = (m*g*tan A)/E
Using given values:
q (5.0*10^-3*9.81*tan 20 deg)/100000
q=1.78*10^-7
therefore, the charge on the ball is 1.78*10^-7
