Question

4. The mutual electrostatic force of attraction between
two small spheres carrying charges +0.4 uC and
-0.8 uC in air is 0.2 N. What is the separation between
the two spheres?
Ans​

Answer 1

Answer:

12 centimetres.

Explanation:

The formula for electrostatic force is given as

$F_e=\frac{1}{4\pi \epsilon}\frac{q_1*q_2}{r^2}$

Putting all the given values in the above formula, we get

$2*10^{-1}=9*10^9*\frac{4*10^{-7}*8*10^{-7}}{r^2}\\\\r^2=\frac{9*10^9*4*10^{-7}*8*10^{-7}}{2*10^{-1}}\\\\r^2=144*10^{-4}\\\\r=12*10^{-2}\,metres=12\,cm$