What is the magnitude of the force between the two charges?

In summary, the magnitude of force between two charges is the measure of the strength of the electric force that exists between them. It is calculated using Coulomb's Law, which states that the force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them. This relationship means that the force decreases as the distance between the charges increases. The type of charges and the medium between them also affect the magnitude of force, with opposite charges resulting in a stronger force and different materials causing different interactions between the charges. The magnitude of force can be calculated using the formula F = k * (q1 * q2)/d^2, where F is the force, k is Coulomb's constant, q
  • #1
yo_man
12
0

Homework Statement



Two positive point charges are 5.20 cm apart.
If the electric potential energy is 71.0 microJoules, what is the magnitude of the force between the two charges?

Homework Equations



potential energy = U = qV
E=kq1q2/r^2
F=qE


The Attempt at a Solution



I've tried manipulating the equations and it does not work. Also, I'm not sure if this has something to do with dipoles
 
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  • #2
The electric potential energy is given by:

[tex] U=\frac{kq_1q_2}{r} [/tex]

Since both charges are the same you can work them out from the potential energy given and then solve for the force.
 
  • #3
?

The magnitude of the force between the two charges can be calculated using the equation F=qE, where F is the force, q is the magnitude of the charges, and E is the electric field. In this case, we can use the electric potential energy equation U=qV to find the electric field E, since the charges are 5.20 cm apart and the electric potential energy is given as 71.0 microJoules. We can rearrange the equation to solve for E:

E = U/q = (71.0 microJoules)/(q)

Next, we can use the equation E=kq1q2/r^2 to substitute in the value for E and solve for the magnitude of the force F:

F = (kq1q2)/r^2 = (8.99 x 10^9 Nm^2/C^2)(q)(q)/(0.0520 m)^2

Since we are given two positive point charges, we can assume that the magnitude of each charge is the same, so we can substitute in q for both q1 and q2. This gives us:

F = (8.99 x 10^9 Nm^2/C^2)(q^2)/(0.0520 m)^2 = 1.55 x 10^-3 N

Therefore, the magnitude of the force between the two charges is 1.55 x 10^-3 N. This force is attractive, as the two charges are positive and will be pulled towards each other. This calculation does not involve dipoles, as dipoles involve two charges with opposite signs and have a different equation for calculating the electric field.
 

1. What is the definition of magnitude of force between two charges?

The magnitude of force between two charges is the measure of the strength of the electric force that exists between them. It is calculated using Coulomb's Law, which states that the force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.

2. How is the magnitude of force between two charges related to the distance between them?

The magnitude of force between two charges is inversely proportional to the square of the distance between them. This means that the force decreases as the distance between the charges increases. Therefore, the closer the charges are, the stronger the force between them will be.

3. Is the magnitude of force between two charges affected by the type of charges or the medium between them?

Yes, the magnitude of force between two charges is affected by both the type of charges and the medium between them. The force is stronger between two charges of opposite polarity and weaker between two charges of the same polarity. The medium between the charges also plays a role, as charges can interact differently in different materials.

4. How can the magnitude of force between two charges be calculated?

The magnitude of force between two charges can be calculated using the formula F = k * (q1 * q2)/d^2, where F is the force, k is Coulomb's constant, q1 and q2 are the charges, and d is the distance between them. This formula is based on Coulomb's Law, which relates the force to the product of the charges and the distance between them.

5. Can the magnitude of force between two charges be negative?

Yes, the magnitude of force between two charges can be negative. This indicates that the force is attractive, meaning that the charges have opposite polarity. If the magnitude of force is positive, it means that the force is repulsive and the charges have the same polarity.

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