Question

Problem Solving: Solve the problem below. Show your solution.

1. Two protons in an atom are 1.75 m x 10 ^-8 m from each other. Calculate the electric force between them.

2. Calculate the magnitude of the electrostatic force between a + 6.0µC charged particle and a + 8.0µC charged particle separated by a distance of 0.7 cm.

3. Two charges attract each other with a force of 90 N. How far a 5.0 x 10^-6 C charge from a -3.0 x 10 ^-5 C charge?

Answer 1

1. The force is

$$F=\frac{1}{4\pi\epsilon_0}·\frac{e·e}{r^2}=7.53·10^{-13}\text{ N}.$$

2. The force is

$$F=\frac{1}{4\pi\epsilon_0}·\frac{q_1q_2}{r^2}=8800\text{ N}.$$

3. The distance can be found from the equation of the force:

$$d=\sqrt{\frac{q_1q_2}{4\pi\epsilon_0F}}=0.12\text{ m}.$$