+ AV Some parts are intended to be independent of each another. If a question requires a previous result, calculation errors will be carried over and the part is marked for correct procedure. 1. A charged ping-pong ball (mass 3.0 x 104 kg) hangs from a light thread 1.0 m long, between two vertical parallel plates d = 0.10 m apart. Gravity acts downwards. When a potential difference of AV = 420.0 V is applied across the plates, the ball swings then comes to rest 0.01 m to one side of its original vertical position (see figure). Consider the problem from a dynamics perspective. a. First, calculate the electric field between the parallel plates. [2 marks] b. What angle does the thread make from the vertical? (Hint: use trigonometry.) [1 mark] C. Draw a free-body diagram for the ball at rest. What forces are involved? [1 mark] d. What is the tension in the thread? [1 mark] 1.0m + + 0.01m + m e. What is the magnitude of the electric force deflecting the ball? [1 mark] f. Using the electric field in (a) and electric force in (e), find the magnitude of the charge on the ball. [2 marks] I I