Wave – a movement of energy through……A medium – the matter (solid liquid or gas) the wave moves through…• Mechanical Waves• 1. Transverse Waves

– Ocean / water waves

• 2. Longitudinal Waves– Sound waves

…A vacuum – as in empty space, yes, outer space.

• Electromagnetic Waves– Light– Micro(waves)– Radio– Ultraviolet– Infrared– Gamma– X-rays

• We will talk more about these later….

Take notes!

Transverse Wave - A wave whose medium to move perpendicular to the direction of the wave

Don’t draw, just look

Transverse Wave - A wave whose medium to move perpendicular to the direction of the wave

• Crest = the “top” of the wave• Trough = the “bottom” of the wave. Think farms, pigs

• Amplitude (labeled “a”) = the energy of the wave. – From resting / equilibrium position to crest / trough– NOT CREST TO TROUGH!

DrawTHIS!! Resting / equilibrium

position

Transverse Wave - A wave whose medium to move perpendicular to the direction of the wave

• Wavelength – the length of the wave– Symbol is Greek lowercase lambda – λ – (think upside down “y”)

– Measured in meters – (m)– From crest to crest, trough to trough, or A resting /

equilibrium position to the next full cycle

Don’t Re- draw, but there is new info..

Resting / equilibrium position

Longitudinal Wave - A wave whose medium to move parallel to (in the same as) the direction of the wave

Don’t draw, just look.PPT should show gif.

Longitudinal Wave - A wave whose medium to move parallel to (in the same as) the direction of the wave

Draw This!Make sure your comp. are drawn thick!

• Crest = Compressions• Trough = Rare factions• Amplitude = the energy of the wave. – How tightly packed the compressions are…– Think about squeezing more and more slinky coils

Longitudinal Wave - A wave whose medium to move parallel to (in the same as) the direction of the wave

• Wavelength – the length of the wave– Symbol is Greek lowercase lambda – λ – (think upside down “y”)

– Measured in meters – (m)

– From compression to compression– trough to trough– The beginning/middle/end of any compressions or rarefaction to…– the same or corresponding beg./mid/end of next compression/

rarefaction

Don’t Re- draw, but there is new info..

Period – the amount of time it takes to complete 1 wave or 1 cycle.

• Period is time!• The standard unit is seconds.• The symbol is a capital letter-t: T• Period for a minute is…• T = 60 s• Period for an hour is • T = 3600 s

Frequency– the number of waves or cycles complete in 1 second.

• Just Watch PPT gif of a transverse wave with an increasing frequency.

Frequency– the number of waves or cycles complete in 1 second.

• Units:• # of waves – is not a unit, it’s just a number, like 1• Units: or

Frequency and Periodlook…

Frequency

• They are inverses!!!

P

• Inverse of x equals 1/x

Velocity of a Wave

• • Units: () (∙ m)

• So yes.. Velocity of wave is in (m/s)