# Error in applying Coulomb's law

• mpatryluk
In summary, the conversation discusses the concept of multiplication of units greater than and less than 1 in relation to coulombs. It is explained that when values are greater than 1, the product of two charges will also be greater than the individual values, but when values are less than 1, the product will decrease. The error in the reasoning is pointed out using an example involving milliCoulombs and microCoulombs. The conversation concludes with a clarification that all values should be expressed in scientific notation in relation to the coulomb unit.
mpatryluk
Well, it's not so much an error as it is a fundamental lack of understanding about multiplication of units greater than vs less than 1.

1. If two charges are repelling each other which have values greater than 1, then the value of q1q2 will be greater than the individual values charge values of each charge. However if the values are less than 1 coulomb, then instead of increasing, the value of q1q2 will decrease from that of the individual charges. How can this be?

2. If I q1 = 0.5 coulombs and q2 = 0.5 coulombs, then q1*q2 = 0.25 coulombs. But if I were to use millicoulombs instead, then 500 mc * 500 mc = 250,000 mc, which = 250C. Where is the error in my reasoning please?

Last edited:
mpatryluk said:
W
2. If I q1 = 0.5 coulombs and q2 = 0.5 coulombs, then q1*q2 = 0.25 coulombs. But if I were to use millicoulombs instead, then 500 mc * 500 mc = 250,000 mc, which = 250C. Where is the error in my reasoning please?

500 milliCoulombs times 500 milliCoulombs is 250,000 microCoulombs. The easiest way to see this is to write all the numbers out in scientific notation using the same units: ##(500\times{10}^{-3})\times(500\times{10}^{-3})=(500\times{500})\times(10^{-3}\times{10}^{-3})=250000\times{10}^{-6}##.

mpatryluk
Ahhh ok, everything has to be expressed in terms of scientific notation in relation to the coulomb being 10^1. I see, thank you.

## 1. What is Coulomb's law?

Coulomb's law is a fundamental law of physics that describes the electrostatic interaction between two charged particles. It states that the force between two charged particles is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.

## 2. What is an error in applying Coulomb's law?

An error in applying Coulomb's law could refer to a mistake in the calculation or interpretation of the law, or an incorrect assumption or approximation made in the application of the law.

## 3. What are some common sources of error in applying Coulomb's law?

Common sources of error in applying Coulomb's law include using incorrect values for the charges or distance between particles, neglecting the effects of other forces, and not considering the limitations of the law in certain situations.

## 4. How can errors in applying Coulomb's law be minimized?

To minimize errors in applying Coulomb's law, it is important to use accurate and precise measurements for the charges and distances, consider all relevant forces, and understand the assumptions and limitations of the law in different scenarios.

## 5. What are the consequences of errors in applying Coulomb's law?

Errors in applying Coulomb's law can lead to incorrect predictions or interpretations of electrostatic interactions, which can impact the accuracy and reliability of scientific experiments and technological applications. It is important to identify and address these errors to ensure the validity of results and conclusions.

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