What is the distance between a$10\mu \mathrm{C}$ charge and a$24\mu \mathrm{C}$ charge if the magnitude of the force between them is $1.2\text{mN}$?

Two protons are 2.0 fm apart. What is the magnitude of the gravitational force on one proton due to the other proton?

If the force between two charges is F when the distance is d, what will the force between the two charges be if they were moved to a distance of 2d?

In which direction will the −1 C charge move? If it has a mass of 10 g, what will its initial acceleration be?

What is the direction of the net force on the charge at the center of the square in the following figure?

Three point charges are arranged along the $x$-axis. Charge $q_1=+3.00$ $\mu$C is at the origin, and charge $q_2=-5.00$ $\mu$C is at $x=0.200$ m. Charge $q_2=-8.00$ $\mu$C. Where is $q_3$ located if the net force on $q_1$ is $7.00$ N in the $-x$-direction?