Two point charges carrying charges q1 = +3 μC and q2 = −4 μC are fixed on the x − y plane at positions (x1 = 3.5 cm, y1 = 0.5 cm) and (x2 = −2 cm, y2 = 1.5 cm) respectively.
a) Find the magnitude and direction of the electrostatic force on charge q2.
b) Where in the x − y plane can you place a third charge q3 = 4 μC, such that the net electrostatic force on charge q2 is zero?

Two conductors, a and b, are each in the shape of a tetrahedron. but of different sizes. they are charged in the following manner: 1. tetrahedron a is charged from an electrostatic generator to charge q. 2. tetrahedron a is briefly touched to tetrahedron b. 3. steps 1 and 2 are repeated until the charge on tetrahedron b reaches a maximum value. if the charge on tetrahedron b was q/4 after the first time it touched tetrahedron a. what is the final charge qbmax on tetrahedron b?