“Repeating disturbances that transfer energy through matter or space.” (11)

 

 

All waves:	Some waves:
·       pass along energy ·       do NOT transport matter ·       are produced by a vibration o     they must have an energy source	·       travel only in a medium o     solid, liquid, gas (matter) o     ex. water waves, sound ·       do not need a medium o     ex. light (travels in space)

 

Mechanical Waves—waves that travel only through matter

Transverse Waves	Compressional Waves
Matter moves back and forth at right angles to the direction that the wave travels (ex. water waves)	Matter moves in the same direction that the wave travels (ex. sound waves)

· Amplitude—measure of the energy in a wave (more energy=bigger A)

o     Compressional waves: how tightly medium is pushed together

· Wavelength (λ)—the distance between one point in the wave and the nearest point just like it (ex. from crest to crest)

· Frequency (f)—how many wavelengths pass a point each second

o     Expressed in hertz (Hz) (ex. 60 Hz = 60 waves per second)

o     frequency equals the rate of vibration of the wave’s source

· Velocity (ν)—how fast the wave moves forward

o     velocity = wavelength x frequency  [ν = λ f ]