When light passes from a denser to a less dense medium, it will typically do what?

• A. Speed up and bend away from the normal
• B. Slow down and bend towards the normal
• C. Speed up and bend towards the normal
• D. Slow down and bend away from the normal

Answer: (A)

When light transitions from a denser medium, such as water or glass, to a less dense medium, like air, it indeed speeds up and bends away from the normal line. This behavior is a result of the refractive index of the materials involved.

The refractive index determines how fast light travels in a medium. A higher refractive index indicates a denser medium where light travels slower. As light exits the denser medium and enters a less dense one, it accelerates, changing its speed. According to Snell's Law, when light moves from a medium with a higher refractive index to one with a lower index, the angle of refraction becomes larger than the angle of incidence. This is interpreted as the light bending away from the normal, which is an imaginary line perpendicular to the boundary between the two media.

Understanding this principle is essential in optics, as it applies to various phenomena such as the bending of light in lenses and the creation of mirages. This concept is fundamental in many applications, including photography and vision correction technologies.