Behavior of Waves Reflection, Refraction, Diffraction and Interference in waves

Reflection Reflection occurs when a wave bounces off of a surface it cannot pass through It is like when a ball hits a wall and bounces back Reflection does not change the speed or frequency of a wave the wave can be flipped upside down if the boundary is fixed

Refraction Refraction is the bending of a wave as it enters a new medium at an angle When a wave enters a new medium at an angle refraction occurs because one side of the wave moves more slowly than the other Refraction occurs only when the two sides of a wave travel at different speeds

Diffraction Diffraction is the bending of a wave as it moves around an obstacle or passes through a narrow opening If the wavelength is small compared to the opening then the diffraction will be little The larger the wavelength compared to the obstacle or opening, the larger the diffraction

Interference Interference occurs when two or more waves overlap and combine together The two types of interference are constructive interference and destructive interference Waves increase in amplitude in constructive interference and decrease in amplitude in destructive interference

Constructive Interference Constructive interference occurs when two or more waves combine to produce a wave with a larger displacement If two transverse waves meet then the crest will be higher and the trough will be lower according to the amplitude of the two waves

Destructive Interference Destructive interference occurs when two or more waves combine to produce a wave with smaller displacements Destructive interference of transverse waves will produce a wave with a smaller crest and trough according to the size of the waves meeting each other

Standing Waves A standing wave is a wave that appears to stay in one place, it does not seem to go through a medium This can be seen if you tie a rope to a chair and shake the other end of the rope, at some point the incoming waves will meet the reflected waves

Nodes and Antinodes A node is a point on a standing wave that has no displacement from the rest position At the node there is complete destructive interference between the incoming and reflected waves An antinode is a point where a crest or trough occurs midway between two nodes

Standing Waves A standing wave forms only if half a wavelength or a multiple of half a wavelength fits exactly into the length of a vibrating cord Once you find the frequency that produces a standing wave, doubling or tripling the frequency will also produce a standing wave