Sphere A has a mass of 4.2 x 10-2 kg and is tethered to a wall by a thin thread. Sphere A has an
excess of 1.2 x 1012 electrons. Sphere B has a deficit
of 3.5 x 1012 electrons and is 0.23 m from sphere A.
Determine the angle between the thread and
the wall.

Two point charges are on the y axis. a 3.90-µc charge is located at y = 1.25 cm, and a -2.4-µc charge is located at y = −1.80 cm. (a) find the total electric potential at the origin. v (b) find the total electric potential at the point whose coordinates are (1.50 cm, 0). v