A small 6.8 g plastic ball is suspended by a
37.3 cm long string in a uniform electric field
of 4790 N/C, as shown.
The acceleration of gravity is 9.8 m/s2 , and
the Coulomb constant is 8.99×109 N · m2/C2..
If the ball is in equilibrium when the string
makes a 11.2◦ angle with the vertical as indicated, what is the net charge on the ball?
Answer in units of μC.