Question

Three charged spheres are at rest in a plane as shown in the figure below. Spheres A and B are fixed, but sphere C, of unknown mass m, is attached to the ceiling by a lightweight thread. The tension in the string is 0.130 N. Spheres A and B have charges

q_A = 47.0 nC

and

q_B = −47.0 nC.

What charge is carried by sphere C?

Three charged spheres are at rest in a plane as shown in the figure below. Spheres A and B are fixed, but sphere C, of unknown mass m, is attached to the ceiling by a lightweight thread. The tension in the string is 0.130 N Spheres A and B have charges qA = 47.0 nC and qB = 47.0 nC what charge is carried by sphere C? 3001 0.230 m Need Help? Read It

Answer 1

Sphere C is moved to the right & top which means it is attached to B (-ive) & repelled by A(+ ive) therefore C must have positive charge F_A = k Vertical-bar q_A Vertical-bar q_c/0.23^2 & F_B = sigma_k Vertical-bar q_B Vertical-bar q_c/0.46^2 sigma F_x = 0 F_B - T sin 30 degrees = 0 k Vertical-bar q_B Vertical-bar q_c/0.46^2 = T sin 30 degrees q_c = T sin 30 degrees (0.46)^2/k Vertical-bar q_B Vertical-bar = (0.130) sin 30 degrees 0.46^2/(9 times 10^9) (47 times 10^-9) = 3.25 times 10^-5 C