1.) A small sphere of charge 2.4 μC experience a force of 0.36 N when a second sphere of unknown charge is placed 5.5 cm from it. What is the charge of the second sphere?

2.) Two identically charged sphere placed 12 cm apart have an electric force of0.28 N between them. What is the charge of each sphere?

3.) In an experience using Coulomb's apparatus, a sphere with a charge of 3.6x10^-8 C is 1.4 cm from a second sphere of unknown charge. The force between the spheres is 2.7x10^-2 N. What is the charge of the second sphere?

4.) The force between a proton and an electron is 3.5x10^-10 N. What is the distance between these two particles

1 answer

These are all Coulomb's law
F = k Q1 Q2/r^2
Just plug in but watch units
2.4*10^-6 Coulombs at .055 meters in prob 1 for example.

k = 9*10^9
e = 1.6*10^-19 Coulombs, negative for electron, positive for proton