## Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (3rd Edition)

The magnitude of the charge on each sphere is $8.2\times 10^{-8}~C$.
We can find the magnitude of the force on each sphere as: $F = ma$ $F = (0.0010~kg)(150~m/s^2)$ $F = 0.15~N$ We can find the magnitude of the charge on each sphere as: $F = \frac{k~q~q}{r^2}$ $q^2 = \frac{F~r^2}{k}$ $q = \sqrt{\frac{F}{k}}~r$ $q = \sqrt{\frac{0.15~N}{9.0\times 10^9~N~m^2/C^2}}~(0.020~m)$ $q = 8.2\times 10^{-8}~C$ The magnitude of the charge on each sphere is $8.2\times 10^{-8}~C$.