Waves Flashcards
Longitudal?
Partictiles , vibrate in the same dirction as the wave, example - sound
Amplitude
Tells us how much energy the wave carries, measured center line to the crest/trough, symbol- A, Unit- m
Transverse
Particles move at a right angle to the direction of travel. Example- Light,water
Wavelength?
Length of a wave, Symbol-λ, unit- m
Period
Time taken to produce 1 wave or time taken for a wave to pass a point, symbol- T, unit- Seconds
Velocity
Distance a wave travels per second, symbol- V,unit ms-1
What are the two types of waves
Transverse and Lomngitudal
Energy Transfer?
Energy is transered through the paricles, the particles don’t move.
Wave?
Waves transfer energy
Frequency of a wave?
f=N/T
What do all waves carry?
Energy
Wave equation?
v=fλ
Frequency?
how many waves are produced per second or how many waves pass a point per second. Symbol-F, unit Hz
Formula for wave speed?
d=vt
Real and apparent depth?
The depth of somthing looks shallower because the light ray is refracted at the surface and the brain assumes the light is in a straight line
Long sight?
Can see distant object cleary, near objects appeared blurred. Convex lens used to make light rays come togheter and focus on retina.
Law of reflection?
The angle of incidence is equal to the angle of reflection?
Short sight?
Distant objects are blurry. Near objects are clear. Concave lens makes the rays seperate and focus on the retina.
Refraction?
When light changes speed going from one substance too another, might also be also a change of direction
What happens when light rays pass into a more dense material?
Slows down, bends towards the normal
What happens when light rays pass into a less dense material?
speed up, bends away from the normal
What happens when light enters a convex lens?
the rays come together
What happens when light enters a concave lens?
Light rays move apart
Where is the angle of incidense
Before entering the substance
Where is the angle of refraction
After entering the substance
Speed of sound in air?
340ms-1
speed of sound in air compared to of states
fastest in solids,liquids then gases
Experiment to measure speed of sound without a computer
Measure sound distance between sound produced and a place, measure the time from the sound being produced and you hearing it. use d=vt to calcute speed
how do noise cancelling headphones work
microphone records noise, electronic device producees opposite signal they cancel out a produce silence
how do hearing aids work
microphone picks up sound, change into a electronic signal, aplifide played through a loud speaker.
speed of sound compared to speed of light
light is faster
3 examples of light being faster than sound
fireworks, thunder storm, any game where a ball is struck
what can sound travel through
anything with paricles, solids,liquids,gases
what can sound not travel through
vaccum of space
what is the range of human hearing
20hz to 20khz
How to meausre the speed of sound using a computer
set up too microphones a known distance apart and connect both too a timer. hit someting at the end of one microphone and record the time then divide the distance by the time to give you the speed
What unit is used to measuere sound levels
decibles(db)
what does a wave with low frequency look like
the waves are longer and spread about more
what does a wave with high frequency look like
the waves are shorter and coloser together
what does a wave with loud sound look like
the amplitued is greater
what does a wave with quiet sound look like
the amplitude is smaller
how do humans hear
a noise is produced this vibrates paricles in the air as the sound wave travels it then enters are ear and vibrates the eardrum
Ultrasound?
have a frequency to high to be heard by humans
ultrasound used in nature, medicine and technology
nature- bats and dolphins use to find food. medicine to take pictures of an unborn baby. technologhy to find the depth of sea.
what is sonar and ultrasound used for?
fishing boats use this to detect fish in the sea
seven parts of the electromagnetic spectrum in order from lowest frequency
Radi, microwave, infra-red,visable light, ultraviolet,x-rays, gamma rays
what speed do electromagnetic waves travel at
speed of light- 300,000,000ms-1
what type of waves are electromagnetic waves
transverse and can travel through a vaccum
what are electromagnetic waves
family of waves, human eye can only detect visable light
what happens to the energy of an electromagnetic wave as the energy increases
the frequency also increases
gamma rays?
detector- geiger-muller tube, use- radiothearpy, danger- cell distruction,mutaion and cancer
x-rays?
detector- photographic film , use- medical scans , danger- cell distruction,mutaion and cancer
ultra-violet?
detector- flurescent materials , use- security marking on bank notes, danger- sunburn skin cancer
visable light
detector- retina , use- lasers, danger- burning, blindness if concentrated
infra-red
detector- thermistor, use- remote controls, danger- burning if concentrated
microwaves
detector- aerial, use- mobile phones, danger- burning if concentrated
radio waves
detector- aerial, use- communications, danger- safe
multiwave astronomy
is the study of how galaxys don’t just give of visbalelight rays but rays accross the electrometic spectrum
