Question

what charged placed 9cm from a charge of 100 micro coulomb will produce a force of 1/9n in air ​

Answer 1

Thank you.....

10^-9 coulomb should be the answer

Answer 2

Answer:

$10^{-9}$ (1 nano) Coulomb of charge.

Explanation:

We are given:

r = 9 cm = $\frac{9}{100} m$

$Q_1 = 100 mC = 100 * 10^{-6} = 10^{-4} C$

$F = \frac{1}{9} N$

We know that-

$F = K \frac{Q_1 Q_2}{r^2}$

Rearranging the equation for finding $Q_2$ we get,

$Q_2 = \frac{Fr^2}{KQ_1}\\ \\ Q_2 = \frac{1 * 81}{9 * 10^4 * 9 * 10^9 * 10^{-4}}$

After solving this we get:

$Q_2 = 10^{-9} C$ = 1n C