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Unit 3 Lesson 3- Behavior of Waves

Some examples of behavior of waves are reflection and refraction

Reflection--

Reflection is a property common to all waves. Reflection occurs when a wave hits an obstacle and bounces back at the same speed. Note that the obstacle will not be another wave, since waves can pass through each other without incident. The angle at which the wave hits the obstacle is called the angle of incidence. The wave will reflect back at the exact same angle, called the angle of reflection. For example, if a wave hits an obstacle at a 45-degree angle, then the wave will reflect back at 45 degrees.

When reflection occurs, the speed of the wave does not change, and the wave essentially flips over on itself. Reflected waves add to the original waves to form patterns. When waves hit a parabola, they reflect at various angles, making the waves focus at the same point in the center of the parabola

Refraction--

Refraction occurs when a wave enters a new medium at an angle and either speeds up or slows down. For example, when light passes through a glass of water, the light will slow down as it passes from the air into the water. Light travels slower in the denser water, and the light waves bend, or refract.

Refraction causes waves to change direction. For example, if an ocean wave hits shallow water at the shore, the wave begins to bunch up. If the wave hits the shallow water at an angle, the part of the wave that hits first will slow down and then drop behind. This makes the wave swing around and change direction.
 

Diffraction--

Diffraction is the bending of the wave as it moves around an object or passes through a narrow opening. A wave diffracts more if its wavelength is large compared to the size of an opening or an obstacle. 

Interference--

Interference is when two or more waves overlap and combine together. Two types of interference are constructive and destructive interference. 

Constructive- happens when two or more waves combine to produce a wave with a larger displacement

Destructive- happens when two or more waves combine to produce a wave with a smaller displacement.