Two spherical metal objects are brought together in a vacuum to a separation distance of 1 mm. If a Coulomb of charge could be placed on one of the objects without any electrical discharge the force of attraction between the two objects would be

A. 9 × 10^12 N
B. 9×10^13 N
C. 9 × 10^14 N
D. 9 × 10^15 N

Two charged particles, q1 and q2, are located on the x-axis, with q1 at the origin and q2 initially at x1 = 12.2 mm. in this configuration, q1 exerts a repulsive force of 2.62 µn on q2. particle q2 is then moved to x2 = 18.0 mm. what is the force (magnitude and direction) that q2 exerts on q1 at this new location? (give the magnitude in µn.)