Question

A distance of 1.0 meter separates the centers of
two small charged spheres. The spheres exert
gravitational force F
g and electrostatic force Fe on
each other. If the distance between the spheres’
centers is increased to 3.0 meters, the
gravitational force and electrostatic force,
respectively, may be represented as
(1) (3) 3F
g and 3Fe
(2) (4) 9Fg and 9Fe

Answer 1

Neither set of choices is correct.

If the distance is tripled, then the forces decrease to

1/9 Fg. and. 1/9 Fe.

Note. When the objects are charged, the gravitational force Fg can almost always be ignored, since Fe is like 10^40 greater when the quantities of mass and charge are similar.