unit 6 - waves and sounds Flashcards
(22 cards)
what types of waves are there
transverse waves and longitudinal waves
feature of transverse waves
the amplitude is perpendicular to the direction of wave travel
move up and down or side to side
feature of longitudinal waves
move backwards and forward
two-section, compression and rarefaction
compression - the area where particles are close together. high air pressure
rarefaction - the area where particles are further apart. low air pressure.
what is frequency
the number of waves passing any point per second. SI unit for frequency is Hz
what is period
the time for one oscillation
formula for frequency
1/period
wave equation
v= f*wavelength
effect of reflection in waves
same wavelength
same speed
same frequency
incident angle=reflection angle
effect of refraction in waves
if it is more shallow - slow down the waves
different wavelength
different speed
different frequency
how does diffraction happen if the gate is smaller or equal to the gap between waves
diffracts like a half-circle
how does diffraction happen if the gate is bigger than the gap between waves
diffracts like a line but with a short edge at the end
how sound waves are made
vibration
sound waves are _______ waves
longitudinal
what sound wave need in order to pass the sound
medium, cannot be vacuum
usual speed of sound in air
330m/s
what are echoes
a reflected sound
high frequency = ______ pitch
high
low frequency = _______ pitch
low
how does energy transferred by waves differ from other transformation of energy
waves transfer energy without transferring matter
what is normal range of human hearing
20-20000 hz
what is ultrasound
above 20000hz
use of ultrasound
scanning womb
