Final answer:
The speed of light decreases as the index of refraction increases. Therefore, the speed of light is slower in glass compared to water.
Step-by-step explanation:
The speed of light in a medium is inversely proportional to the index of refraction of that medium. The index of refraction measures how much the speed of light slows down when passing through a material. As the index of refraction increases, the speed of light decreases. Therefore, the speed of light is slower in glass (with an index of refraction of 1.55) compared to water (with an index of refraction of 1.3). The index of refraction is directly related to the speed of light in different media. When light enters a medium with a higher index of refraction, it slows down compared to its speed in a vacuum. Given that the index of refraction for water is 1.333 and for glass is 1.52, light travels slower in glass than in water. Speed of light in water is approximately 2.25×10¸ m/s, while in glass, it is about 1.97×10¸ m/s.