# Reflection and refraction of light

In opticsrefraction is a phenomenon that often occurs when waves travel from a medium with a given refractive index to a medium with another at an oblique angle.

The Doppler Effect Previously in Lesson 3the behavior of waves traveling along a rope from a more dense medium to a less dense medium and vice versa was discussed. The wave doesn't just stop when it reaches the end of the medium.

Rather, a wave will undergo certain behaviors when it encounters the end of the medium. Specifically, there will be some reflection off the boundary and some transmission into the new medium.

But what if the wave is traveling in a two-dimensional medium such as a water wave traveling through ocean water?

## Refraction - Wikipedia

Or what if the wave is traveling in a three-dimensional medium such as a sound wave or a light wave traveling through air? What types of behaviors can be expected of such two- and three-dimensional waves? The study of waves in two dimensions is often done using a ripple tank. A ripple tank is a large glass-bottomed tank of water that is used to study the behavior of water waves.

A light typically shines upon the water from above and illuminates a white sheet of paper placed directly below the tank. A portion of light is absorbed by the water as it passes through the tank. A crest of water will absorb more light than a trough. So the bright spots represent wave troughs and the dark spots represent wave crests.

As the water waves move through the ripple tank, the dark and bright spots move as well. As the waves encounter obstacles in their path, their behavior can be observed by watching the movement of the dark and bright spots on the sheet of paper. Ripple tank demonstrations are commonly done in a Physics class in order to discuss the principles underlying the reflection, refraction, and diffraction of waves.

Reflection of Waves If a linear object attached to an oscillator bobs back and forth within the water, it becomes a source of straight waves. These straight waves have alternating crests and troughs.

As viewed on the sheet of paper below the tank, the crests are the dark lines stretching across the paper and the troughs are the bright lines. These waves will travel through the water until they encounter an obstacle - such as the wall of the tank or an object placed within the water.

The diagram at the right depicts a series of straight waves approaching a long barrier extending at an angle across the tank of water. The direction that these wavefronts straight-line crests are traveling through the water is represented by the blue arrow.

The blue arrow is called a ray and is drawn perpendicular to the wavefronts.Knowing the difference between reflection and refraction will help you understand basic phenomenon of science. Reflection, is when the light goes back to the previous medium, but changes direction.

On the flip side, refraction is when light is absorbed by the medium but the direction and speed is affected. Notice the paths of light of the convex and concave lenses shown below. Directions: Answer the questions about reflection and refraction.

occurs when light bounces off an object. occurs when light is bent. When light strikes a surface that is rough, the light will. A light ray with an angle of incidence equal to or greater than the critical angle will reflect, following the law of reflection.

The interactive illustration at the top of this page explores patterns of reflection and refraction of light rays that hit a variety of interfaces at different angles of incidence. The light rays pass through each raindrop and then go through a process of reflection and refraction as they exit.

The entire process causes white light to split into its various different colors, and it appears as a rainbow to us down on Earth. Refraction of Light. Refraction is the bending of a wave when it enters a medium where its speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the normal to the boundary between the two media.

Refraction is the bending of light rays. Normally, light travels in a straight line, and changes direction and speed when it passes from one transparent medium to another, such as from air into glass.

The reflection and refraction of light