# Magnitude of electric force on a proton

• Sox281212
In summary, the magnitude of the electric force on one proton due to the other proton is 37 N. This can be determined using the formula Fe = K|q1||q2| / r2, where q1 and q2 are the charges of the two protons (1.6 x 10^-19 C) and r is the distance between them (2.5 fm). Both protons have the same charge, 1.6 x 10^-19 C, as they are both positively charged particles. This is because the charge of an electron and a proton are equal in magnitude but opposite in sign, making them neutral when combined in an atom.
Sox281212

## Homework Statement

Two protons are 2.5fm apart.
What is the magnitude of the electric force on one proton due to the other proton?

## Homework Equations

Fe = K|q1||q2| / r2

## The Attempt at a Solution

Fe = (9 x 109)x(1.6 x 10-19)2 / (2.5 x 10-15)2
Fe = 37 N

I got the answer but I don't understand why I am able to use e= 1.6 x 10-19 as q1 and q2? could someone explain? thanks

Because both protons have this charge.

Sox281212 said:
I got the answer but I don't understand why I am able to use e= 1.6 x 10-19 as q1 and q2? could someone explain? thanks
You have two charges:
q1 = 1.6e-19C
q2 = 1.6e-19C
why wouldn't the formula F = kq1q2/r2 apply here?

Wait, I'm confused.. isn't 1.6 x 10^-19 the charge of an electron?! Oh wait, is it because charge of electron = charge of proton if its neutral?

Sox281212 said:
Wait, I'm confused.. isn't 1.6 x 10^-19 the charge of an electron?! Oh wait, is it because charge of electron = charge of proton if its neutral?

+1.6 x 10^-19 C is the charge of a proton. -1.6 x 10^-19 C is the charge of an electron. They are the same magnitude but of opposite sign. Also note that the unit is important, 1.6 x 10^-19 is not a charge, it is a number.

Thank you so much, that cleared things up :)

Sox281212 said:
Wait, I'm confused.. isn't 1.6 x 10^-19 the charge of an electron?! Oh wait, is it because charge of electron = charge of proton if its neutral?
Charge of electron = -charge of proton. The thing that's neutral is the atom, comprising electrons, equal number of protons yielding the "neutrality", plus possibly neutrons which have no charge. ( The exception is ions which do have a net charge. Example: add salt to water, you get mostly sodium and chlorine ions).

## 1. What is the magnitude of electric force on a proton?

The magnitude of electric force on a proton is equal to the product of its charge and the electric field it is placed in. This can be represented by the formula F = qE, where F is the force in newtons (N), q is the charge of the proton (1.6 x 10^-19 coulombs), and E is the electric field strength in volts per meter (V/m).

## 2. How is the magnitude of electric force on a proton affected by distance?

The magnitude of electric force on a proton is inversely proportional to the square of the distance between the proton and the source of the electric field. This means that as the distance increases, the force decreases. This relationship can be represented by the formula F = kqQ/r^2, where k is the Coulomb's constant (8.99 x 10^9 Nm^2/C^2), Q is the charge of the source of the electric field, and r is the distance between the proton and the source.

## 3. What is the direction of the electric force on a proton?

The direction of the electric force on a proton is always towards or away from the source of the electric field, depending on the sign of the charge. If the proton has a positive charge, the force will be directed away from the source, while if the proton has a negative charge, the force will be directed towards the source. This direction can be determined using the right-hand rule, where the fingers point in the direction of the electric field and the thumb points in the direction of the force.

## 4. How is the magnitude of electric force on a proton affected by the strength of the electric field?

The magnitude of electric force on a proton is directly proportional to the strength of the electric field it is placed in. This means that as the electric field strength increases, the force on the proton also increases. This relationship can be represented by the formula F = qE, where q is the charge of the proton and E is the electric field strength.

## 5. How does the magnitude of electric force on a proton compare to the magnitude of gravitational force on a proton?

The magnitude of electric force on a proton is much stronger than the magnitude of gravitational force on a proton. For example, the electric force between two protons that are 1 meter apart is approximately 10^36 times stronger than the gravitational force between them. This is because the electric force is dependent on the charges of the particles, which are much larger compared to their masses that determine gravitational force.

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