Physics question

Question

Two electrical charges, 20 cm apart exert forces on each other. If the charges are moved a distance of only 5 cm apart the force they each feel will be

A. 1/4 as great

B. 1/2 as great

C. 4 times is great

D. 16 times as great

Answer 1

The electric force is an inverse square law given by Coulombs Law, which states that the force is inversely proportional to the square of the distance. Thus, if the new distance is 1/4 of the original distance (5 = 1/4 * 20), then the new force will be 16 times greater than the original force (1 / (1/4)² = 1 / (1/16) = 16).