Question

Two 200 pounds lead ball are separated by the distance of 1 meter .both ball have sam positive charge q.what charge will produce in electrostatic force between the that is of the same order of magnitude as the weight of one ball.

Answer 1

First, convert 200 pounds to kilograms: multiply 200 by 0.454: 90.7 kg.

Second, calculate the weight of the ball:

$$P=mg.$$

On the other hand, this force must be equal to the force of electrostatic interaction:

$$P=mg=\frac{1}{4\pi\epsilon_0}\frac{q^2}{r^2},\\ \space\\ q=2r\sqrt{mg\pi\epsilon_0}=2\cdot1\sqrt{90.7\cdot9.8\cdot3.14}=106\text{ C}.$$