# Physics question ?

A student is investigating Coulomb’s law. The student measures a force of +2.00×10^-3 N between the two charged spheres.

a. Describe the law that Charles Coulomb used as the basis of his hypothesis.

b. Describe two methods the student could use to increase the force to 64 times its current value. Your answer should include numerical values for clarity.

c. The student touches one of the spheres with a neutral sphere of equal size and then removes the neutral sphere. The student then moves one of the spheres so the distance is four times the original distance. What is the ratio of the original force to the new force?

### 1 Answer

- NCSLv 71 month agoFavorite Answer
a. Not sure what they're going for here, but Coulomb's law of attraction looks a lot like Newton's law of gravitation, that the attraction force between two masses is directly proportional to each of the masses and inversely proportional to the square of the distance.

b. F = k*Q*q / d²

so to get 64 times the force you could either

(i) multiply the product of the masses by 64, or(ii) divide the separation distance by 8

c. Assuming all the spheres are conductors, then removing the previously neutral sphere removes half of the charge from the sphere that was touched, cutting the force in half. Quadrupling the distance further reduces the force by a factor of 16. The new force is 1/32 of the original force.

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