Behavior of Waves

At what wavelengths can a standing wave form in an elastic cord?

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.

What determines how much a wave diffracts when it encounters an opening or an obstacle?

A wave diffracts more if its wavelength is large compared to the size of an opening or obstacle.

How is a wave changed by reflection?

Reflection does not change the speed or frequency of a wave, but the wave can be flipped upside down.

List the types of interference.

Two types of interference are constructive interference and destructive interference.

What causes refraction when a wave enters a medium at an angle?

When a wave enters a medium at an angle, refraction occurs because one side of the wave moves more slowly than the other side.

How does the frequency of a reflected wave compare to the frequency of the incoming wave?

While a reflecting wave loses speed and force, an incoming wave has more speed because it has not been stopped by anything.

How are diffraction and refraction similar? How are they different?

While a refraction is when a wave falls in on its self, a diffraction is when a wave passes through an obstacle.

Node

a point on a standing wave that has no displacement from the rest position

Antinode

a point where a crest or trough occurs midway between two nodes

Standing wave

a wave that appears to stay in one place

Refraction

the bending of a wave as it enters a new medium at an angle

Diffraction

the bending of a wave as it moves around an obstacle or passes through a narrow opening

Reflection

when a wave bounces off a surface that it cannot pass through

Constructive interference

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

Destructive Interference

when two or more waves combine to produce a wave with a smaller displacements

Interference

when two or more waves overlap and combine together