Two charged dust particles exert a force of 9.0 ✕ 10-2 n on each other. what will be the force if they are moved so they are only one-ninth as far apart?

Dust particles exert Force on each other F = 9.0 • 10^-2 N

The particles are moved by 1/9 th as far. We have equation for force and distance when two particles involved that is F = K q1 q2 / r^2.

So Force is inversely proportional to r^2, so the new r is r / 9, then the force becomes r^2 times the previous force.

New Force = 81 x 9.0 âś• 10^-2 = 729 x 10^-2 = 7.29 N