WAVES Flashcards
what is a wave?
a transfer of energy
what is a longitudinal wave?
a wave in which the vibrations travel parallel to the wave direction
e.g. sound waves
what is a transverse wave?
a wave in which the vibrations travel perpendicular to the wave direction
e.g. light and radio waves
what is the wave called when its bunched up?
compression
whats the wave called when its spread out/not bunched up?
rarefraction
what is a mechanical wave?
a wave which requires particles e.g. sound wave
what is an electromagnetic wave?
a wave which doesn’t require particles
what is the wavelength?
the same point on 2 adjacent waves
what is frequency?
the number of waves per second
measured in Hz
what is period?
the time it takes for 1 wave to pass by
how to use a ripple tank?
look at shadows add pointer and count how many waves pass in 10 seconds divide by 10 measure distance with ruler use calculation
what happens when sound increases?
amplitude increases which causes the waves to look taller
what is the healthy hearing range for humans?
20 - 20,000 Hz
what occurs on a rough surface?
diffuse scattering
what occurs on a smooth surface?
specular reflection
how do sound waves work to hear sounds?
waves enter ear (longitudinal)
sound waves cause ear drum to vibrate
vibrations are turned into electrical signals
electrical signals sent to the brain
what happens when a wave enters a more dense material?
bends towards normal line
slows down
wavelength decreases
what happens when a wave enters a less dense material?
bends away from normal line
speeds up
what is the law in the refraction RP?
angle of incidence = angle or reflection
what is an ultrasound?
wave with a higher frequency than the upper limit of humans
how do ultrasounds work?
pass ultrasound through material
wave hits boundary and is reflected back
time taken for reflection to reach detector used to produce image
what is echo sounding?
high frequency sound
time how long it takes for reflection to reach detector used to measure how deep water is
what is an S seismic wave?
transverse
in solids
what is a P seismic wave?
longitudinal
liquids + solids
travels faster in solids than liquids
