Two charges repel each other with a force of 10^-6 N when they are 10 cm apart. When they are brought closer together until they are 2 cm apart, the force between them becomes

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Quizplus · Accepted Answer

The force between two charges is given by Coulomb's law, $F = k \frac{q_1 q_2}{r^2}$, where $F$ is the force, $k$ is Coulomb's constant, $q_1$ and $q_2$ are the charges, and $r$ is the distance between the charges. When the distance between the charges is reduced from 10 cm to 2 cm, the distance is reduced by a factor of 5. Since the force is inversely proportional to the square of the distance, reducing the distance by a factor of 5 increases the force by a factor of $5^2 = 25$. Therefore, the new force is $10 \times 10^{-6} N \times 25 = 2.5 \times 10^{-5} N$.

Two Charges Repel Each Other with a Force of 10-6

Two Charges Repel Each Other with a Force of 10^-6