Two tiny conducting spheres are identical and carry charges of -20.0 C and +50.0 C. They are

Question:

Two tiny conducting spheres are identical and carry charges of -20.0 µC and +50.0 µC. They are separated by a distance of 2.50 cm.
(a)What is the magnitude of the force that each sphere experiences, and is the force attractive or repulsive?
(b) The spheres are brought into contact and then separated to a distance of 2.50 cm. Determine the magnitude of the force that each sphere now experiences, and state whether the force is attractive or repulsive.