Question

Why is electromagnetic force greater then gravitational force?

Answer 1

That is only true for objects on the atomic scale. For celestial bodies, gravitational forces dominates.

Explanation:

The gravitational force is directly proportional to the mass of both objects. The electrostatic force is directly proportional to the charge of the objects.

Mathematically,

`F_"g" = frac{GMm}{r^2}`

and

`F_"e" = frac{kQq}{r^2}`.

For objects on the atomic scale, for example electrons, they have little mass, but relatively large charge. Therefore, electromagnetic forces dominates

For objects on the macroscopic scale such as stars, they have overall little net charge in comparison to their huge mass. Therefore, gravitational forces dominates.