Figure 20-30 shows a charge q = +6.77 μC with a mass m = 0.071 kg suspended by a thread of...

Figure 20-30 shows a charge q = +6.77 μC with a mass m = 0.071 kg suspended by a thread of length L = 0.022 m between the plates of a capacitor. (a) Plot the electric potential energy of the system as a function of the angle θ the thread makes with the vertical. (The electric field between the plates has a magnitude E = 4.16 × 104 V/m.) (b) Repeat part (a) for tine case of the gravitational potential energy of the system. (c) Show that the total potential energy of the system (electric plus gravitational) is a minimum when the angle θ satisfies the equilibrium condition for the charge, tan θ = qE/mg. This relation implies that θ = 22°.

FIGURE 20-30 Problem