Question

Two tiny conducting spheres are identical and carry charges of -19.8

Answer 1

a) Opposite charges attract.

F = (k*q1*q2)/r^2 = (8.99e9)(-19.8*10^-6)(46.5*10^-6)/(0.0237 m)^2 = abs(-1.47*10^4 N) = 1.47*10^4 N

b) When brought into contact, they will equalize charge. Thus, (19.8 + 46.5)/2 = 33.15 microcouloumbs exchanged (gained negative charge on positive sphere and lost negative on negative sphere). -19.8 + 33.15 = +13.35 microcouloumbs.

Same charge, thus they both repel.

F = (k * q1 * q2)/r^2 = (8.99e9)(13.35*10^-6)(13.35*10^-6)/(0.0237)... = 2852.5 N