Final answer:
When light passes through a glass prism, it separates into its component colors due to different velocities of the colors in glass.
Step-by-step explanation:
When light passes from air to a glass prism, it undergoes refraction, which causes the light to bend and separate into its component colors. This phenomenon is known as dispersion. The reason for this is that different colors of light have different wavelengths, and when light enters the prism, each color is refracted at a slightly different angle due to the variation in its wavelength.
The component colors have different velocities in glass because each color has a different refractive index in the glass. The refractive index of a material determines how much the light is bent or refracted when it passes through it. Since different colors have different refractive indices in glass, they will travel at different speeds and bend at different angles.
Therefore, option A is the correct answer: The component colors have different velocities in glass.
Learn more about Refraction of light