Ch. 13 Waves and Vibrations

matching word column part

periodic motion

any motion that repeats itself over same distance

simple harmonic motion

any type of motion that repeats itself along the same path b/c of restoring force potential to its displacement

vibration

wiggle in time only (back and forth)

frequency

number of cycles per unit of time

period

time for one cycle

pulse

one single vibration that moves through medium

wave

many pulses together that move through medium

sine wave

a pictorial representation of a wave

crest

high point of sine wave

trough

low point on sine wave

equilibrium

at rest or mid point position

amplitude

max displacement from equilibrium (measures strength of wave)

wavelength

distance between two identical successive parts of a wave

medium

what the wave is traveling through

• speed a wave travels depends on the medium

• only energy of wave is transported from one point to another, not medium

mechanical wave

wave that needs a medium (water, sound)

electromagnetic wave

wave that doesn’t need medium (light)

transverse

disturbance moves perpendicular to wave motion

longitudinal

disturbance moves in the same direction as wave motion

compression

area of high pressure

rarefaction

area of low pressure

surface wave

motion of both transverse and longitudinal waves

principle of superposition

when 2 waves try to occupy the same point, displacement of medium is sum of displacement caused by individual wave

interference

2+ waves try to occupy same point in space at same time, interfere but no affect on one another

in phase

when similar parts of wave arrive together ( 2 crests/troughs)

out of phase

when opposite parts of wave arrive together ( 1 crest/trough)

constructive

waves arrive in phase and interfere resulting in a wave of increased amplitude

destructive

wave arrive out of phase and interfere resulting in wave with decreased amplitude

standing wave

when 2 identical waves moving in opposite directions of each other interfere

nodes

parts of wave that don’t appear to move

anti-node

parts of wave that moves a lot

damped harmonic motion

decreases amplitude of the mass over time

under-damped

slowly decreases amplitude while continuing to oscillate

over-damped

may not return to equilibrium position for quite some time without oscillating

critically damped

returns to equilibrium position very quickly without excessive oscillations

resonance

includes a driving force that matches the natural vibration and would increase the amplitude