Q:
# Why does light refract or bend when going through glass or water?

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### Quick Answer

**Light refracts when it passes through the boundary of two dissimilar materials because the speed and wavelength of light changes in different media.** Light does not refract when crossing between two media of identical refractive indicies, or when it falls perpendicular to the interface.

The refraction of light from a medium where it travels faster to a medium where it travels slower is in the direction of the normal to the interface. This form of refraction occurs when light travels from air to water or glass because it is faster in the former than the latter. Light traveling from a slower medium to a faster one refracts away from the normal to the interface. The degree of refraction from the slower medium to the faster one is equal and opposite to the refraction from the faster to the slower one. The degree of refraction between two media is quantified by their respective indices of refraction. As the value of the relative refractive index between two media increases, the degree of refraction of a light ray crossing the interface between the two media also increases. Light refraction is governed by Snell’s Law, which states that the refractive indices between two media is proportional to the inverse of the sines of the incident and emergent angles of a light ray relative to the normal.

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Q:
## What is the relationship between speed, distance and time?

A:The speed of an object is equal to the distance traveled divided by the time taken to travel that distance. The faster an object is moving, the further it moves in the same amount of time.

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Q:
## How fast is the speed of sound?

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Full Answer >**The speed of sound in dry air is approximately 344 meters per second, or 770 miles per hour.**This assumes dry air at sea level with a temperature of 68 degrees Fahrenheit.Filed Under: -
Q:
## What is the equation for speed?

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Full Answer >**The most common equation for speed is: speed = distance / time.**It can also be expressed as the time derivative of the distance traveled. Mathematically, it can be written as v = s/t, or v = (ds/dt), where speed is denoted by v, distance is denoted by s, and time is denoted by t. In case of uniform velocity, the first equation is used.Filed Under: -
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## What is the formula for speed?

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Full Answer >**The formula for speed is s = d/t, where s equals the speed, d is the distance covered and t is the time it took to cover the distance.**The formula for finding the instantaneous speed at a specific point is found by taking the derivative of the speed equation.Filed Under: