Question

The table lists the values of the electrical force and the gravitational force between two protons.

How do the electrical force and the gravitational force compare?

The electrical force is 1.2 × 1036 times greater than the gravitational force, and both forces are attractive.
The electrical force is 1.2 × 1036 times greater than the gravitational force, but only the gravitational force is attractive.
The electrical force is 8.0 × 10–37 times greater than the gravitational force, and both forces are attractive.
The electrical force is 8.0 × 10–37 times greater than the gravitational force, but only the gravitational force is attractive.

Answer 1

Answer: b

Step-by-step explanation:

Answer 2

The electrical force between two protons is given by:

`F_e = k (e^2)/(r^2)`
where

`k=8.99 \cdot 10^9 Nm^2C^(-2)` is the Coulomb's constant

`e=1.6 \cdot 10^(-19)C` is the proton charge
r is the separation between the two protons

The gravitational force between the two protons is given by:

`F_g=G (m^2)/(r^2)`
where

`G=6.67 \cdot 10^(-11) m^3 kg^(-1) s^(-2)` is the gravitational constant

`m=1.67 \cdot 10^(-27) kg` is the proton mass
r is the separation between the two protons

If we divide the electric force by the gravitational force, we get

`(F_e)/(F_g)= (k)/(G) (e^2)/(m^2)=1.2 \cdot 10^(36)`

which means that the electric force between the two protons is
`1.2 \cdot 10^(36)` times greater than the gravitational force.

Moreover, the two protons have same electric charge, and the electrostatic force between two same-sign charges is repulsive, while the gravitational force is always attractive: therefore, the correct answer is
The electrical force is 1.2 × 1036 times greater than the gravitational force, but only the gravitational force is attractive.