The definition of Coulomb's law is the force between two static point charges in vacuum, but since there is a force, will it still be static, and in vacuum The definition of Coulomb's law is the force between two static point charges in vacuum, but since there is a force, will it still be static, and there is no friction and electrostatic force to balance in vacuum. If gravity and electrostatic force balance, it is not a complete case

The definition of Coulomb's law is the force between two static point charges in vacuum, but since there is a force, will it still be static, and in vacuum The definition of Coulomb's law is the force between two static point charges in vacuum, but since there is a force, will it still be static, and there is no friction and electrostatic force to balance in vacuum. If gravity and electrostatic force balance, it is not a complete case

If the object placed on the ground receives gravity, will it still stand still? I feel that the question you ask is similar to this. If it is still, there must be other forces to maintain its equilibrium state. Why bother about how it is balanced? Coulomb's law does not require that it be in vacuum, but in different media, K requires different standstill because of motion

F in the formula of Coulomb's law is proportional to q1q2. How to get it?

The formula can be obtained directly, and the formula can be obtained by experiment

The electrostatic attraction is 0.3n when the distance r between two identical metal spheres is + 3 times 10-8 Coulomb and - 5 times 10-8 Coulomb
Now the electric quantity of two identical metal balls is + 3C and - 5C respectively, and the electrostatic force at the distance r is 0.3n. Now when the two balls are in contact and then placed in the original position, what is the electrostatic force between them? Is it gravity or repulsion?
Can you give me a more detailed answer? Why the electrostatic force becomes - 1 Coulomb after contact,

0.3＝3*5/r^2
r^2=50
The electrostatic force after contact is half of the sum of the original two electrostatic forces, (3 + (- 5)) / 2 = - 1
The electrostatic force between them is - 1C, which is repulsive force
F＝1/50
=0.02N

When Q2 is released and Q2 only moves under the action of the Coulomb force of Q1, the Coulomb force ()
A. Keep decreasing B. keep increasing C. keep unchanged D. first increase and then decrease

The charged ball with the same charge is repulsed, so the distance is farther and farther. Because the electric quantity remains unchanged, according to f = & nbsp; kq1q2r2, the electric field force will gradually decrease with the distance increasing, so BCD is wrong, a is correct, so a is selected

In vacuum, Q1 and Q2 with different point charges are placed at two points a and B respectively. It is known that their Coulomb force is 10N, Q1 = - 1 * 10 ^ - 2, Q2 = - 2 * 10 ^ - 2
If Q1 is removed, the field strength of Q2 at a is in? Direction? If Q2 is removed, the field strength of Q1 at B is in? Direction?

From F = (kq1q2) / (R * r)
Calculate R * r = 180000
There is a formula of electric field intensity produced by point charge in textbook, E1 = (kq1) / (R * r), E2 = (KQ2) / (R * r)
So E1 = 500 N / C
E2＝1000 N/C
Is this the right way of thinking

Coulomb's law?

Coulomb's Law: the force between two static point charges in a vacuum is proportional to the product of the charged quantity of the two charges, and the direction of the force follows this direction
The formula: F = k * {(Q1 * Q2) / (R * r)} * e
Experimental verification of Coulomb's Law: Coulomb's law was summed up by Coulomb's NewBalance experiment from 1784 to 1785. The structure of NewBalance is shown in the figure below. A scale pole is suspended under a thin wire. There is a small ball a at one end and a balance body P at the other end. Beside a, there is another fixed ball B of the same size as it. In order to study the force between charged bodies, a and B are charged, At this time, the scale rod will deflect due to the force on the a-end. Turn the hanging button on the top of the hanging wire to make the ball return to its original position. At this time, the torsion moment of the hanging wire is equal to the torque of the electric power applied to the ball A. if the relationship between the torsion moment of the hanging wire and the torsion angle has been calibrated in advance, the angle reading of the pointer on the knob and the known length of the scale rod, We can know the force between a and B at this distance

What is Coulomb's theory

In the study of earth pressure theory, the shape of rupture surface is assumed, and the earth pressure is determined according to the static equilibrium condition of rupture prism in limit state. This kind of earth pressure theory was first put forward by c.a.coulomb of France in 1773, which is called Coulomb theory

Two charged metal balls with the same radius made of the same material, the absolute value of the charge of one ball is five times that of the other, and the Coulomb force between them is F. now put the two balls back to the original place after contact, the Coulomb force between them may be ()
A. 5F9B. 4F5C. 5F4D. 9F5

If two charges are the same, let the charge of one ball be q, then the charge of the other ball be 5q, and then f = k5q2r2, which is separated after contact, and the charge is 3Q respectively, then the Coulomb force of the two balls f ′ = k9q2r2 = 9f5; If the two charges are different and separate after contact, the absolute value of the electric quantity of the two balls is 2q, and the Coulomb force of the two balls is f ′ = k4q2r2 = 45F. Therefore, B and D are correct, and a and C are wrong. Therefore, BD is selected

What's the name of K in Coulomb's law?
Coulomb's law f = K (q1q2) / R ^ 2
Where R is the distance and q1q2 is the number of charges
So, what's the name of K? I just want to know the name!

Electrostatic constant

The distance between the centers of two charged metal spheres with radius R is l (L = 4R)
A. It is greater with the same kind of charge than with different kinds of charge B. It is greater with different kinds of charge than with the same kind of charge C. It is greater with the same amount of negative charge than with the same amount of positive charge D

A. When charged with the same kind of charge, it can be seen from the meaning that the distance between two balls causes the ball to be unable to be regarded as a point charge. Then, according to the mutual attraction of different kinds of charges and the mutual exclusion of the same kind of charges, it can be seen that the distance with different kinds of charges is less than the distance with the same kind of charges. Therefore, according to the formula of Coulomb force law: F = kqqr2, it can be seen that the Coulomb force with different kinds of charges is greater than that with the same kind of charges, so AC error, According to the expression of Coulomb's law, the content of Coulomb's law is: the interaction force between two static point charges in vacuum is directly proportional to the product of their charge quantity and inversely proportional to the quadratic power of their distance, and the direction of the force is on the line between two points of charge