Phys Chapter 20 vocab

Sound

a form of energy that exists whether or not it is heard

Propagation speed

rate at which sound travels through a medium, aka velocity or speed

Reflection

a process in which sound encountering a surface or a change in medium is returned

Refraction

Bending of waves caused by changes in speed

Forced vibrations

setting up of vibrations in an object by a vibrating force

Natural frequency

own unique frequency

Resonance

frequency of forced vibrations = different object's natural frequency

Interference

a property of all waves and wave motion

Constructive interference

increased amplitude when the crest of one wave overlaps the crest of another wave

Destructive interference

reduced amplitude when the crest of one wave overlaps the trough of another wave

Beats

periodic variations in the loudness of sound due to interference

Demodulation

the process of extracting the low doppler frequencies from the high transducer frequency