P3 - waves (general wave properties, electromagnetic spectrums) Flashcards
2 types of waves
-longitudinal
-transverse
where is most and least number of particles in longitudinal wave
-most: compression
-least: rarefaction
where is most and least pressure in longitudinal wave
-most: compression
-least: rarefaction
define oscillations
-max displacement of a wave
(vibrations)
what are the oscillations in a transverse and longitudinal wave to direction of wave motion
-transverse: perpendicular to direction of wave motion
-longitudinal: parallel to direction of wave motion
how to the particles vibrate in transverse and longitudinal
-transverse: up and down
-longitudinal: right and left
define amplitude
max displacement between the peak/ trough and position of equilibrium
define equilibrium
position where displacement is 0
what is wave length in transverse and longitudinal
-transverse: distance btw 2 adjacent peaks/ troughs
-longitudinal: distance btw 2 adjacent rarefactions/ compressions
which wave type requires a medium to travel through and why
-longitudinal
-need matter to compress and rarefy to propagate to direction of wave travel
what can direction of wave motion also be called
direction of energy transfer
define a wave
-disturbance that transfers of energy without transferring matter away form source
label parts of a longitudinal wave
-rarefaction
-compressions
-direction of wave motion/ energy transfer
what are transverse waves over on their diagrams
distance or time
what is the top and bottom parts of a transverse wave called
-peak/ crest
-trough
label parts of a transverse wave
-peak/ crest
-trough
-position of equilibrium
-amplitude
what is oscillations in transverse
from peak to trough
eg of longitudinal waves
-sound
-Seismic P wave
eg of transverse waves
-water waves
-Seismic S (secondary) wave
-electromagnetic spectrum
define period
time taken for 1 wave length
define frequency
number of wave lengths per second
what is Frequency measured in
-Hertz
-Hz
what is period measured in
-seconds
-s
what is the frequency of electricity
50- 60 Hz
define wave speed
speed which wave travels in
formula for wave speed
V = fλ
V= velocity (ms^-1)
f=frequency (Hz)
λ= wave length (m)
formula for period
T = 1/ f
T= time (s)
f= frequency (Hz)
what is λ
-lambda
-wave length
how to change Km/h to m/s
-multiply by 1000
-divide by 3600
standard form in order
nano- 10^-9
kilo- 10^3
mega- 10^6
Giga- 10^9
sound wave:
-type of wave
-how produced
-medium or not?
-longitudinal; mechanical
-by vibration objects
-need medium
can sound travel through a vacuum
-no
-no particles in a vacuum
how does the frequency of sound change as it travels
its constant
how does the wave speed vary depending on states of matter for mechanical waves
-solid: fastest; most densely packed medium
-liquid
-gas: least; particles are far apart
-vacuum: no motion; no particles
speed of all electromagnetic waves
3 x 10^8 ms^-1
how does pitch change as frequency changes
-more frequency, higher pitch
how does loudness change as amplitude changes
-more amplitude, more loudness
can electromagnetic wave travel through vacuum
yes; all as same speed
formula to find distance
v= d/t
v= velocity (ms^-1)
d= distance (m)
t=time (s)
how does wave length affect pitch
-shorter wave length, more frequency, higher pitch
frequency of animal hearing
below 20Hz (infrasound)
frequency of human hearing
20- 20 000Hz
frequency of bat hearing
20 000- 1MHz (Ultrasound)
what does UV stand for
Ultra Violet light
what are y-rays
gamma rays
define echoes
reflected sound
designing experiment for sound
-person with cymbal and another with stopwatch with 100m btw
-cymbals clashes and person starts timer and ends when they hear sound
-works because of diff. speed of light and sound
designing experiment for echo
-1 person with cymbals and another with stopwatch 350m in front of a wall
-start stopwatch when cymbals clash and end when hear sound again
what happens to the distance in echos
doubled
does sound travel faster in cold or warm air
cold; more dense
does sound travel faster in solids or gas
solids; more dense
how is sound heard around conners
sound is diffracted
define an oscilloscope
apparatus that converts longitudinal waves to transverse waves
what happens to sound waves when they strike a hard surface
some is:
-absorbed
-reflected
-refracted
-transmitted
define wave front
-set of all locations in a medium where the wave is at the same place
-imaginary surface representing points in a wave that are in the same point in their cycle
-peaks of waves
-lines are equal
can electromagnetic waves travel in vacuum- at what speed
yes, 3 x 10^8
waves in electromagnetic spectrum in order of increasing frequency
-radio
-micro
-inferred
-visible light
-Ultra Violet (UV)
-X- rays
-Gama rays (y- rays)
waves in electromagnetic spectrum in order of increasing wave length
-Gamma rays (y- rays)
-X- rays
-Ultra Violet (UV)
-Visible light
-inferred
-micro
-radio
what happens to frequency as wave length of electromagnetic waves increase
increased wave length, less frequency
what does high frequency in electromagnetic waves mean
high energy
uses for radio waves
-radio transmission
-TV transmission
-Radar
-Wifi
-bluetooth
-(is diffracted by hills)
uses for micro waves
-Satellite TV
-microwave ovens
-mobile phones
uses for inferred waves
-TV remoter controllers
-projector controller
-thermal imaging
-inferred cameras
uses for visible light waves
-vision
-photography
uses for UV rays
-detect forged bank notes
-in sunlight
-(cause fluorescence)
uses for X- rays
-medical scanning
-airport security scanning
uses for Gamma rays
-detect cancer
-cancer treatment
-(can pass through dense metals)
what is the relationship btw energy, wave length,frequency and pitch for electromagnetic waves
high energy, less wave length, more frequency, higher pitch
harmful effects of UV, X- rays, Y- rays
UV: cause skin cancer, eye problems
X-rays & Y- rays: cause cell mutations, damage cell
4 properties of electromagnetic waves
-transverse waves
-3 x 10^8 ms^-1 speed
-partly electrical, partly magnetic
-all travel through vacuum
colours in visible light starting with lowest frequency/ longest wave length
-ROYGBIV
-Red
-Orange
-Yellow
-Green
-Blue
-Indigo
-Violet
how is speed changed from deep to shallow water
decrease in speed
define ultrasound
sound with frequency higher than 20 000Hz
uses for ultrasound
-pregnancy scans
define infrasound
sound with frequency lower than 20Hz
speed of sound in temps of air
warm air - fast v
cold air - slow v
