Question

Two tiny conducting spheres are identical and carry charges of -18.8 µC and +46.5 µC. They are separated by a distance of 2.47 cm. (a) What is the magnitude of the force that each sphere experiences, and is the force attractive or repulsive? N

Answer 1

Answer:

$F=-12896N$, attractive.

Explanation:

For calculating this force we use the Coulomb Law:

$F=\frac{kq_1q_1}{r^2}$

Where $k=9\times10^9Nm^2/C^{-2}$ is the Coulomb's constant, $q_1$ and $q_2$ the values of each charge and r the distance between them.

Since the Coulomb's constant as I wrote it is in S.I. we have to write all the magnitudes in that system of units, and substitute:

$F=\frac{(9\times10^9Nm^2/C^{-2})(-18.8\times10^{-6}C)(46.5\times10^{-6}C)}{(0.0247m)^2}=-12896N$

This force is attractive since both charges are of opposite sign.