Review your understanding of Coulomb's law and electric forces in this free article aligned to NGSS standards.
|Electric charge||A property of matter that determines the force on the object when placed in an electromagnetic field. Objects can have positive, negative, or neutral charge. Like energy and matter, total electric charge is conserved, and charge cannot be created or destroyed.|
|The electric force constant, or Coulomb’s constant, which has a value of .|
|Equation||Symbol breakdown||Meaning in words|
|is electric force, is the Coulomb’s law constant, and are the charges, and is the distance between the charges.||The magnitude of the electric force between and is directly proportional to the magnitude of the charges and inversely proportional to the square of the distance between them. This equation is known as Coulomb’s Law.|
Comparing electric force and gravitational force
Coulomb's law may look somewhat familiar, because it has a lot in common with Newton's law of gravitation:
Like gravitational force, whose magnitude increases with mass, electric force magnitude increases with the magnitude of the charges. Both forces act along the imaginary line joining the objects. Both forces are inversely proportional to the square of the distance between the objects, this is known as the inverse-square law. Also, both forces have proportionality constants. uses and uses , where .
A difference between gravitational force and electric force is their relative strengths, related to the ratio of to . The electrostatic force between an electron and a proton is many orders of magnitude greater than the gravitational force between them.
Direction of electric force
The electric force can be either attractive or repulsive. Opposite charges, such as a positive charge and a negative charge, attract each other. Like charges, such as two negative charges or two positive charges, will repel each other.
What else should I know about Coulomb's law?
- Electric force is inversely proportional to instead of . As the distance between charges increases, the electric force decreases by a factor of . For example, if we double the distance between the two electrons, the repulsive force between them would reduce (because it is inverse), and it would go down by a factor of instead of (because of the square).
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- is r measured in cm? if not, what unit?(1 vote)
- in "CGS" system [centi;gram;second] r is measured in centimeters but in "MKS" system [meter;kilo;second] r is measured in meters(3 votes)
- How do I find the Electric field if the charge is not given but distance is?(4 votes)
- Will an object with more charge have a greater force than the object with a smaller charge?(2 votes)
- An object with greater charge will exert a greater force on an object than an object with smaller charge would. However, if you consider two charges that exert a force on each other, regardless of the magnitude of charge, both charges will exert an equal force on each other because of Newton's third law.(2 votes)
- Is there any derivation of relation needed for comparision of Gravtitational and Electrostatic Energy(1 vote)
- when am i actually going to use this irl??(1 vote)
- What is the direction of force between a proton and an electron?
Please explain your answer(1 vote)
- A proton has a positive charge and an electron has a negative charge. This means that they will attract each other. So the force on the electron will point towards the proton and the force on the proton will point towards the electron.(1 vote)
- How would I use thee formula to find the electric field(1 vote)
E-Electric field in Newton per Coulomb
F-Force in Newton
q-Charge in Coulomb on which the electrostatic force is exerted(1 vote)
- How does the charge of an electron compare to the charge of a
- They compare by pushing against each other which causes them to connect or become magnetic while for a proton delivers a positive charge an electron delivers a negative charge which is attracted to each other. But why is this?
Well because of Coulomb's law supported by Faraday's law which shows that when the electric charge creates an electric field, this affects the charges that exist in that region which means that opposite charges connect while similar charges push against each other by means of E = Fe / Q2 = (10N / 2C) = 5 N / C(1 vote)