Answer:
[tex]q=1\times10^{-8}C[/tex]
Explanation:
Let the charge on the ball bearing is q.
charge on glass bead, Q = 20 nC = 20 x 10^-9 C
Force between them, F = 0.018 N
Distance between them, d = 1 cm = 0.01 m
By use of Coulomb's law in electrostatics
[tex]F=\frac{KQq}{d^{2}}[/tex]
By substituting the values
[tex]0.018=\frac{9\times10^{9}\times20\times10^{-9}q}{0.01^{2}}[/tex]
[tex]q=1\times10^{-8}C[/tex]
Thus, the charge on the ball bearing is [tex]q=1\times10^{-8}C[/tex]
