Light travels at 3.0 × 108 m/s in a vacuum and slows to 2.0 × 108 m/s in glass. what is the index of refraction of glass?

The index of refraction,n= 1.5

Explanation:

Index of refraction, n is given by:

n = c/ v

Given: c = speed of light= 3.0×10^8m/s

v= speed of light in glass= 2.0×10^8m/s

n= (3.0×10^8)/(2.0×10^8)

n= 1.5

explanation: magnetic pole, region at each end of a magnet where the external magnetic field is strongest. the south-seeking pole, or any pole similar to it, is called a south magnetic pole. unlike poles of different magnets attract each other; like poles repel each other.

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me