# Speed of light in different media

• vrus
In summary, the conversation is about the speaker's homework to find the refractive index of light in various mediums and their urgency to get the measurements in km/s. They ask for help in finding the speed of light in air, water, diamond, and Perspex, and are advised to use Google for the answers.
vrus
Light is not my most favouite topic, but I am forced to do it at school !

Anyway, my homework was to find the refracting index of light in water, air, diamond and perspex. But they said we have to show the working out !

So can anyone please tell me the speed of light in :-
(i) Air
(ii) Water
(iii) Diamond
(iv) Perspex
This is urgent !
I require it in km/s.
Thanks !

First look for refractive indexes of all the mediums you referred above.

then refractive index of a medium= speed of light in vacuum/speed of light in that medium

Speed of light in vacuum = 300000000 m/s

vrus,

So can anyone please tell me the speed of light in :-

(i) Air
(ii) Water
(iii) Diamond
(iv) Perspex

Here are the answers:

(i) google: speed of light in air
(ii) google: speed of light in water
(iii) google: speed of light in diamond
(iv) google: speed of light in Perspex

Google is your friend! Learn to use it.

## What is the speed of light in different media?

The speed of light is a fundamental constant in physics and is defined as approximately 299,792,458 meters per second in a vacuum. However, the speed of light can vary when traveling through different materials, such as air, water, or glass.

## Why does the speed of light change in different media?

The speed of light changes in different media because of the interaction between light and the atoms or molecules in the material. When light enters a medium, it is absorbed and re-emitted by the atoms, causing a delay in its speed.

## How does the speed of light in different media affect our perception?

The change in the speed of light can affect how we perceive objects. For example, when light travels through a denser medium, such as water, it appears to bend or refract. This is why objects underwater may appear closer or distorted.

## Can the speed of light in different media be greater than the speed of light in a vacuum?

No, according to Einstein's theory of relativity, the speed of light in a vacuum is the maximum speed at which anything can travel. The speed of light in any other medium will always be slower than the speed of light in a vacuum.

## How is the speed of light in different media measured?

The speed of light in different media is measured using a variety of methods, including the use of lasers, interferometers, and refractometers. These instruments allow scientists to precisely measure the time it takes for light to travel through a specific medium and calculate its speed.

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