In the figure four particles form a square with edge length a = 3.02 × 10-2 m. The charges are q₁ = 94 = 2.37 × 10-15 ℃ and 92 = 93 = q. (a) What is q if the net electrostatic force on particle 1 is zero? (b) Is there any value of q that makes the net electrostatic force on each of the four particles zero?

In the figure three identical conducting spheres form an equilateral triangle of side length d = 28.6 cm. The sphere radii are much smaller than d and the sphere charges are qA = -2.55 nC, q = -4.50 nC, and qc = +6.98 nC. (a) What is the magnitude of the electrostatic force between spheres A and C? The following steps are taken: A and B are connected by a thin wire and then disconnected; B is grounded by the wire, and the wire is then removed; B and C are connected by the wire and then disconnected. What now are the magnitudes of the electrostatic force (b) between spheres A and C and (c) between spheres B and C? (a) Number i (b) Number i (c) Number i Units Units Units < <

In the figure four particles are fixed along an x axis, separated by distances d = 3.80 cm. The charges are q₁ = +4e, q2 = -e, 93 = +e, and 94 = +12e, with e = 1.60 × 10-19 C. What is the value of the net electrostatic force on (a) particle 1 and (b) particle 2 due to the other particles? (a) Number i (b) Number i Units 1 Units d 2 d 3 d 4

Three particles are fixed on an x axis. Particle 1 of charge q₁ is at x = -a and particle 2 of charge q2 is at x = +a. If their net electrostatic force on particle 3 of charge Q is to be zero, what must be the ratio 91/92 when particle 3 is at (a)x=+0.663a and (b)x=+1.760? (a) Number (b) Number Units Units