How does the speed of light in a substance such as glass compare with the speed of light in a vacuum?
A) The speed of light in glass is faster than the speed of light in a vacuum.
B) The speed of light is the same in both, equal to 299,792.458 km/s.
C) The speed of light in glass is slower than the speed of light in a vacuum.
D) The speed of light in glass can be faster or slower than the speed of light in a vacuum, depending on the type of glass.

Question

Quizplus · Accepted Answer

The speed of light in a substance such as glass is slower than the speed of light in a vacuum. This is due to the fact that the atoms and molecules in the substance interfere with the light waves, causing them to slow down. The degree of slowing down depends on the refractive index of the substance.

How Does the Speed of Light in a Substance Such