(Solved): (25%) Problem 4: Tuo positively-charged balls with equal amounts of charge, each with mass m=4.28 ...

$(25\%)$ Problem 4: Tuo positively-charged balls with equal amounts of charge, each with mass $m=4.28\mathrm{g}$ a are suspended from the ceiling by a thread of length $L=1.39\mathrm{m}$, as shown: $25\%$ Part (a) Consider the forees acting on the ball shown on the right in the drawing. Which one of the following choices best represents the free-body diagran for this situation? D $25\%$ Part (b) Enter an expression for the sum of the forces in the horizontal direction acting on the ball on the right in the drawiag in terms of the magnitud the tension, $T$, the magnitude of the electrie forec, $F_E$, and the angle $?$. A $25\%$ Part (c) Enter an expression for the sum of the forces in the vertical direction acting on the ball on the right in the drawing. A $25\%$ Part (d) If each thread makes an angle $?=7,42^{?}$ with respect to the vertical direction, what is the magnitude, in microcoulombs, of the charge $q$ on each ball?