Protons experience both electric and gravitational forces. Comparing the forces between 2 protons in a nucleus, it is correct to state that

Question

A electric force is much stronger than the gravitational force

B gravitational force is much stronger that the electric force

C electric force is shorter range than the gravitational force

D gravitational force is shorter range than the electric force

Answer 1

Consider the nucleus of a Helium atom (2 protons). The size of the nucleus is about 10^-15 m so let's assume that's the distance between the protons as a rough cut. The mass of a proton is 1.7 × 10^-27 kilograms. The electrical charge (q) of a proton is 1.6 x 10^-19 coulombs.

Gravitational force is calculated by F_G = Gm₁m₂/d²

where G, the Gravitational Constant, is 6.67^-11 m³/s²/kg so:

F_G = (6.67^-11)(1.7 × 10^-27)(1.7 × 10^-27)/(10^-15)² ≈ 2 x 10^-34 N

Electrical force is calculated by F_E = kq₁q₂/d²

where k, Coulomb's constant, is 9 x 10⁹ N m²/C² so:

F_E = (9 x 10⁹)(1.6 x 10^-19)(1.6 x 10^-19)/(10^-15)² ≈ 200 N

So it's fair to say that the electrical force is MUCH greater than the gravitational force (note that these two forces act in opposite directions)