Question

Two equal charges repel one another with a force of 0.5N when separated 50cm apart in a vacuum. Calculate the value of each charge.( K=9×10^9m/F)

Answer 1

Force acting on the charge particle is given by :

$f \: = \frac{k \: q1 \: q2}{r {}^{2} }$

charge are equal in quantity hence

$0.5 \: = \frac{9 \times 10 {}^{9} \times q {}^{2} }{2500 \: \times 10 {}^{ - 4} }$

$q {}^{2} = \frac{0.125}{9 \times 10 {}^{9} }$

$q {}^{2} = \frac{125}{9} \times 10 {}^{ - 12}$

$q = \frac{5 \sqrt{5} }{3} \times 10 {}^{ - 6}$

Hence the value of each charge is

$\frac{5 \sqrt{5} }{3} \times 10 {}^{ - 6}$