Answer to Question #205274 in Electricity and Magnetism for Akul

Question

 Two charged particles apply an electric force of 5.2×10 −3 N on each other. Distance between them gets twice as much as before. What will be Coulomb's force?

Answer 1

Gives

$F_1=5.2\times10^{-3} N$

$F_2=?$

$r_2=2r_1$

$F_1=\frac{kq_1q_2}{r_1^2}=5.2\times10^{-3}N$

$r_2=2r_1$

$\frac{F_2}{F_1}=\frac{\frac{kq_1q_2}{r_2^2}}{\frac{kq_1q_2}{r_1^2}}$

$\frac{F_2}{F_1}=\frac{r_1^2}{(2r_2)^2}=\frac{1}{4}$

$F_2=\frac{F_1}{4}=\frac{5.2\times 10^{-3}}{4}$

$F_2=1.3\times10^{-3}N$