How do gravitational force and electrical force compare?

Answer 1

Regarding their relative strength, this is the example I always like to give:

You've got some bits of tissue on the table. You run a rubber comb through your

hair and pass it over the bits of tissue. They jump up off the table to the comb.

The gravitational force of the whole Earth is pulling them down, and the electrostatic

force of a charged pocket comb is pulling them up. And the comb wins.

Compared to the gravitational force between a pair of 1-kilogram masses, the

electric force between a pair of 1-coulomb charges the same distance apart is

about 10,000,000,000,000,000,000,000,000,000,000,000,000,000 times as strong.

As my freshman Physics prof used to tell us: If every kilogram of mass in the Earth

and your body were coulombs of charge instead, then when you slipped on the ice,

you'd fall down, just as you do now, but you'd fall 1040 harder.

Answer 2

Gravitational force acts between any two objects with mass, while electrical force acts between charged objects. Gravitational force is always attractive and depends on mass and distance, while electrical force can be attractive or repulsive and depends on charge and distance. Both forces follow an inverse square law.