Calculation of field strength by Coulomb force formula

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2. F is the Coulomb force, which refers to the force on the test charge in the specified electric field. When the specified electric field is a point charge electric field, f = kqq / r2 can be used to calculate (R is the distance between the test charge and the central charge). If it is a uniform electric field, this formula can not be used. The title will definitely tell you one of E or F, and then they can be converted to each other

3. Coulomb force is just the interaction between two charges at rest
the electric field force F refers to the interaction force between any two charged bodies
the electric field strength e refers to the force of unit point charge in the electric field generated by a charged body
Coulomb force: F = kq1q2 / R ^ 2 (for square), q1q2 is the charge quantity of two point charges, positive charge is positive, negative charge is negative. If their proct is positive, then the Coulomb force is positive and it is repulsive; On the contrary, it is gravity.

4. Coulomb force formula F = K (q1q2) ÷ R?? (electrostatic constant k = 9.0) × 10^9
N·m??／ C?? ) general formula of electric field intensity: e = f ÷ Q
point charge field strength formula: e = KQ ÷ R??
uniform electric field strength formula: e = u ÷ D capacitance formula C = q ÷ U= ε S ÷ four π kd

5. Coulomb force is also called electric field force, f field strength is the abbreviation of electric field strength, expressed by E. Electric field strength is used to describe the properties of electric field force, f = QE. The work done by the electric field force: w = FS = QED (Note: D is the projection of the line connecting two points in the electric field on the electric field line) the electric field line actually does not exist. It is used to describe the electric field. The density of the electric field line indicates the magnitude of the electric field intensity, and the tangent direction on the curve indicates the direction of the electric field intensity. It can be said that its function is to describe the size and direction of the field strength. Along the direction of the electric field line, the potential decreases graally. Doing work is accompanied by the change of energy, so when electric field force does work, electric potential energy will also change. When electric field force does positive work, electric potential energy will decrease. When the electric field force does negative work, the electric potential energy increases Wab=Ea-Eb> o. Positive work, the potential energy at the beginning of point a is greater than that at the end of point B, indicating that the final potential energy is reced.) The potential is relative, because the reference point is usually the ground, and the potential difference is absolute. The potential difference is the difference between the potentials of two points, which can also be expressed by w / Q. the potential on the equipotential surface is equal, the work done by the electric field force on the equipotential surface is zero, the potential difference between adjacent equipotential surfaces is equal, and the density of the equipotential surface can also indicate the size of the field strength, The relationship between electric field strength and electric potential difference is u = ed. there are three methods to calculate electric field strength, e = f / Q (applicable to any electric field strength) = KQ / R square (applicable to vacuum) = u / D (uniform electric field), and electric potential difference, u = w / Q = EA EB = ed

6.

One electric quantity is Q & # 39; The electrostatic force F of another point charge with Q can be expressed as F = Ke * QQ & # 39/ R ^ 2, where R is the distance between two point charges and Ke is the Coulomb constant

in vacuum, the interaction force between two static point charges Q1 and Q2 is directly proportional to the proct of Q1 and Q2, and inversely proportional to the square of the distance r between them. The direction of the interaction force is along their line. The same kind of charges repel each other and the different kinds of charges attract each other

extended data:

Coulomb's law was proposed by French physicist Coulomb in 1785 in the paper "law of electricity". Coulomb's law is the first quantitative law in the history of the development of electricity and one of the basic laws of electromagnetism and electromagnetic field theory

Coulomb's law is not only the basic law of electromagnetism, but also one of the basic laws of physics. Coulomb's law clarifies the law of interaction between charged bodies, determines the properties of electrostatic field, and lays the foundation for the whole electromagnetism. The influence of Coulomb's work on French physicists can also be confirmed by Laplace's brief program of physics later

the basic starting point of this brief program of physics is to simplify all physical phenomena as the phenomena of attraction and repulsion between particles, and the motion of electricity or magnetism is the effect of attraction and repulsion between charged particles or magnetic particles. This simplification facilitates the application of analytical mathematics to physics

7. The direction of Coulomb force on the positive charge is the direction of the field strength at the change point
electric field strength e:
the ratio of the electric field force F on the detection charge to the electric quantity Q of the detection charge is called the electric field strength at the point
e = f / Q
the electric field strength is a vector
it stipulates that the direction of the electric field strength is the same as that of the electric field force on the positive charge at the point, And the direction of the electric field force on the negative charge at this point is opposite

8. Coulomb force potential energy is also called electric potential energy
calculation formula EP = Q φ
potential: a physical quantity that describes the energy properties of an electric field. Potential refers to the ability of any two points in the electric field to do work on the charge
the potential is relative to the potential energy. Take infinity as the zero potential point,
φ= KQ / R
it can be seen that the potential of each point in the electric field formed by positive point charge is positive, and that of each point in the electric field formed by negative point charge is negative.

9. Vector is a quantity with size and direction, such as electric field strength and electric field force in electricity
while scalar is a quantity with size and no direction, such as electric potential difference in electricity
in the calculation formula of uniform electric field, you don't take positive and negative first, because it's easy to make mistakes, so you can take all positive. After calculating the answer, you can simply judge the relationship between the direction and the positive direction. For example, if u = e * D, e is a vector and u is a scalar, it is easy to make mistakes in calculating the potential difference between two points. This is my suggestion that we should work out the result, and then compare the direction of the distance from a to B with the direction of the electric field line. If the same direction is positive and the reverse direction is negative, we can get the correct answer
PS: I am only a junior in high school. If there is anything I don't understand, please make friends with my peers

10. In vacuum, the interaction force between two static point charges Q1 and Q2 is directly proportional to the proct of Q1 and Q2, and inversely proportional to the square of the distance r between them. The direction of the interaction force is along their line. The same charges repel each other and the different charges attract each other. F = kq1q2 / R ^ 2
note the condition of Coulomb's Law: in vacuum, it must be a static point charge
the electric field force is the force exerted on the charge when it is placed in the electric field. Or the force exerted in an electric field to move a free charge
F = QE
it is applicable to the calculation of all electric field forces