1. What is the magnitude of the electric force of attraction between an iron nucleus (q = +26e) and its closest electron if the distance between them is 1.5*10-13 m? If you assume the electron is orbiting the nucleus (it doesn’t), determine how fast that electron is going. (0.27 N, 0.7c)

The magnitude of the electric force is 0.27N, and the speed of the electron is 211,000,000 m/s, about 0.7c.

Explanation:

According to Coulomb's Law, we have that:

It means that the force of attraction between the nucleus and the electron is 0.27N.

Now, from the definition of centripetal force, we have:

Considering that the mass of an electron is 9.1*10^-31 kg, and we know the magnitude of the electric force and the distance r, we can calculate the speed of the electron:

Having that the speed of light is about 3*10^8 m/s, then the speed of the electron is 0.7c.

v 154.9= 0.9 length length s little over 154.9cm