A particle moves across the page from left to right in the presence of a uniform electric field directed toward the top of the page. Determine the type of charge and the direction of a uniform magnetic field that could result in a zero net force on the moving charge.

Uppose we consider the system of the three capacitors as a single "equivalent" capacitor. given the charges of the three individual capacitors calculated in the previous part, find the total charge qtot for this equivalent capacitor. express your answer in terms of v and c.