A parallel plate capacitor on Earth has a horizontal electric field E between the plates. A small object with a mass of 21 g and a charge of -3.90 μC is suspended by a thread between the plates. The thread makes an angle of 12.1° with the vertical. (Diagram to the right)
a. Draw the free body diagram for the object. Be sure to label all forces and angles. Establish a coordinate system and determine components of forces in that coordinate system.
b. Write the Newton's 2nd Law equation(s).
c. Find the tension in the thread.
d. Find the magnitude of the electric field.