A wave is a vibration / disturbance that transports energy (not matter)
A pulse is a single vibration that makes a wave, a pulse wave. Repeated pulses creates continuous or periodic waves
The two types of waves are mechanical and electromagnetic
mechanical waves require a medium to travel through, such as air or water.
electromagnetic waves do not need a medium to propagate, but can travel through a medium if one is present
The two types of mechanical waves are transverse and longitudinal waves.
a transverse wave's motion is perpendicular to the motion of the particles in the medium.
a longitudinal wave's motion is parallel to the motion of the particles in the medium (ex: sound wave).
As energy travels, it causes the particles in the medium to be displaced, a wave is not matter in itself.
The crest is the highest point in a wave.
The trough is the lowest point in a wave.
Equilibrium is the point where the medium rests if there was no wave.
A wavelength is the horizontal distance in a wave cycle measured in meters.
A wave cycle is the complete oscillation of a wave from its maximum to its minimum, returning to the same point in the same direction (up or down).
Amplitude is the maximum displacement of a wave from equilibrium, which shows how much energy the wave is transporting, measured in meters.
Frequency is the number of completed wave cycles in one second, measured in Hertz (Hz).
If velocity is a constant and frequency increases, the wavelength will decrease.
Period (T) is the amount of time needed to complete one full wave cycle, measured in seconds.
Wave speed is its velocity, measured in meters per second.
The velocity of a wave depends only on the nature of the medium it's travelling through.
When the medium changes, the frequency stays the same, but the wavelength changes.
If the medium changes and the velocity of the wave increases, the wavelength will increase.
wavefronts are lines that represent the crests of a wave. The distance between each wavefront is a wavelength.
Rays show a wave's direction of motion. They are drawn perpendicular to wavefronts.
When a wave hits a boundary, reflection, refraction, or diffraction occurs.
A boundary is the point where a wave leaves one medium and enters another.
Reflection is when a wave encounters a boundary, part of its energy will enter the new medium, while part will "bounce back", returning to the original medium.
When encountering a boundary, the initial wave is the incident wave.
When encountering a boundary, the portion of the wave that enters the new medium is called the transmitted wave.
When encountering a boundary, The part of the wave that bounces back into the original medium is called the reflected wave.
the degree of difference in densities of media determines how much of the incident wave is reflected.
When encountering a boundary, the more similar the densities are, the more the incident wave will be transmitted. If the media have very different densities, most of the incident wave will be reflected.
When going from a less dense medium to a more dense medium, the reflected wave will be inverted.
When going from a more dense medium to a less dense medium, no inversion will occur in the reflected wave.
When a wave hits a fixed solid object, some is reflected and transmitted. The reflected end is inverted.
If the end of a medium is left free, the reflected waves are not inverted.
When going into a denser medium, the velocity and wavelength decrease. The opposite is true when entering a lighter medium.
When wave speed changes as it enters a new medium, it also causes the wave to change direction, called refraction.
Diffraction occurs when waves bend when they encounter obstacles or pass through openings.
When a wave encounters an obstacle bigger than the wavelength, little diffraction occurs.