Why c is divided while converting cgs into SI system?

In summary: For example, 200 cm/s is equivalent to 2 m/s. In summary, when converting from cgs to SI units, the velocity of light is divided because of factors such as 1/(4\pi\epsilon_0) and the difference between the original absolute Ampere and the SI Ampere, which involve the use of c. This is also historically linked to the ratio between natural electric charges in magnetic and electrostatic phenomena. When converting between units, it is important to pay attention to all multiplying factors to avoid confusion.
  • #1
RAFIQ MULLA
1
0
In conversion of formula from cgs into SI, usually c, the velocity of light is divided. Why it is so?
 
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  • #2
Hi RAFIQ. Welcome to the forum.

You need to explain a little more. What is divided by what? Can you give an example?

In converting from cgs into SI, usually there is no division of c or by c. So it is very confusing what you mean.
 
  • #3
How many cms are there in a m? Your answer could involve that, perhaps.
Conversions between units can be tricky unless you are scrupulous with all your multiplying factors.
 
  • #4
[itex]1/(4\pi\epsilon_0)[/itex] in SI units is equal to c^2, with factors of ten coming in in the conversion from cgs to MKS.T his comes from [itex]\epsilon_0\times \mu_0=1/c^2[/itex]. [itex]\mu_0[/itex] is not a fundamental constant, but just comes from
[itex]\mu_0/4\pi=10^{-7}[/itex] with the factor [itex]10^{-7}[/itex] coming from the different units. There is also a factor of ten due to the difference between the original absolute Ampere and the SI Ampere.
Historically, the c came as the ratio between the electric charge that was natural for the current in magnetic phenomena and the electric charge that occurred in electrostatic phenomena. In order to use only one charge, the factor c was introduced.
 
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  • #5
100 cm/s = 1 m/s because 100 centimeters are one meter.
The same applies to multiples of this speed.
 

Related to Why c is divided while converting cgs into SI system?

1. Why is c divided while converting cgs into SI system?

The cgs system (centimeter-gram-second) and the SI system (International System of Units) use different units for measuring speed. In the cgs system, speed is measured in centimeters per second (cm/s), while in the SI system, it is measured in meters per second (m/s). Therefore, when converting from cgs to SI, c (the speed of light in a vacuum) is divided to account for the difference in units.

2. Can't we just use the same unit for speed in both cgs and SI systems?

While it may seem simpler to use the same unit for speed in both systems, the cgs system is not as widely used as the SI system. Additionally, the SI system is considered to be more precise and consistent. Therefore, it is important to make the conversion to ensure accuracy and consistency when using measurements in different systems.

3. Why is the speed of light used in the conversion from cgs to SI?

The speed of light (c) is a fundamental constant in physics and is the maximum speed at which all matter and information in the universe can travel. Using this constant in the conversion ensures that all measurements in the cgs system are accurately and consistently converted to the SI system.

4. What other units are converted when converting from cgs to SI?

In addition to speed, other common units that are converted when converting from cgs to SI include length (cm to m), mass (g to kg), force (dyn to N), and energy (erg to J).

5. Are there any exceptions to the conversion from cgs to SI?

While the conversion from cgs to SI is generally straightforward, there are a few exceptions to note. For example, some quantities, such as viscosity and magnetic field strength, have different units in the two systems and require additional conversion factors. Additionally, some equations may have different forms in the cgs and SI systems. It is important to consult a conversion chart or formula guide to ensure accuracy when converting between the two systems.

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