A negative charge of 2.0 x 10-4 C and a positive charge of 8.0 x 10-4 C are separated by 0.30 m. What is the magnitude of the force between the charges? Is this force repulsive or attractive?

Question

A negative charge of 2.0 x 10-4 C and a positive charge of 8.0 x 10-4 C are separated by 0.30 m. What is the magnitude of the force between the charges? Is this force repulsive or attractive?

Answer 1

Hi Jenson,

You can use Coulomb's law: F_e = kq₁q₂/r². That is, Coulomb's constant k, times the absolute value of the product of both charges, all divided by the squared distance between them. This will give you the force between them. You just need to plug in all those knowns into the equation.

Now is this force repulsive or attractive? What happens when you put two negative sides of a magnet together? They repel. And a negative and positive attract. The same concept applies to charges. So a positive and negative charge will attract.

I hope that helps! Let me know if you have any other questions.