waves test study guide Flashcards
amplitude
- maximum distance away from the rest position (equilibrium).
- equilibrium position to the crest or equilibrium position to the trough
compression
as a vibrating object swings forward, it creates a compression in the medium that moves outward.
rare fraction
when the vibrating object swings backwards, the air molecules are spread out. they can be drawn as troughs from a transverse wave
doppler effect
the doppler effect is the change in frequency of a wave (or other periodic event) for an observer moving relative to the wave source. the wavelength in the back of the sound’s source increases while the frequency decreases, and the opposite is true as well.
medium
- mechanical waves are waves that travel through matter.
- As energy moves through the medium in the form of a wave, the particles in the medium vibrate around their rest position.
- sound waves need a medium in order to travel through.
pitch
the term that describes a high or low sound
frequency
defined as the number of vibrations a wave makes per second.
longitudinal
waves that vibrate the medium parallel to the direction of the wave
refraction
refractions are the change in the direction of a wave due to a change in the transmission medium
ex: pencil in water
pulse
a single disturbance that moves outward.
transverse
transverse mechanical waves vibrate at a right angle to the direction that the wave moves.
reflection
when a wave strikes a boundary or an obstacle and bounces back towards the source, the wave and the energy it transports is reflected
period
- the time it takes for one vibration or one full wavelength to occur.
- period and frequency are inversely related to each other.
diffraction
the apparent bending of waves around small obstacles and the spreading out of waves past small openings
transmission
when waves hit a boundary, not all of it is reflected. some of the wave goes through the new material.
interference (constructive interference and destructive interference)
- constructive: waves that line up to each other are considered in phase. these waves will add up in amplitude to reinforce each other and they get bigger.
- destructive: waves that are out of phase (do not line up) with each other will cancel out their amplitudes and they get smaller.
wavelength
is defined as the distance it takes a wave to complete one up and down motion/vibration.