500
Two spheres, one with a charge of -Q and the other with a charge of +2Q are separated by a distance R, and exert a force F on each other. The spheres are now altered so that the force between them is 2F. Which of the following would have produced this result?
a) The charge on both spheres was doubled
b) The charge on only one sphere was increased by a factor of 4
c) The charge on both spheres was doubled, and the distance between them halved
d) The charge on only one sphere was halved, and the distance between them halved
e) The charge on both spheres was increased by a factor of 4, and distance between them doubled
d) The charge on only one sphere was halved, and the distance between them halved