4. (20 pts) A charged insulating sphere is suspended by a string with length L = 2.0 m at an angle of 30 in a homogeneous electric field E = 2.0 10N/C. The sphere has mass m = 0.004 kg. L q E (a) (5 points) What is the sign of the charge suspended in the electric field? Include a free-body diagram of the forces on charge q. (b) (10 points) What is the charge on the plastic ball suspended in the electric field? C (c) (5 points) If the length of the string were halved, would the angle increase, decrease, or stay the same? State your answer and then explain.