Topic 2 - Waves Flashcards
What does a longitudinal wave look like?
))) ) ) ) ))) ) ) ) )))
What does a travserve wave look like?
Wavy like multiple sidways s
What does water transfer?
transfers energy, vibrations and causes oscillations
what is the deffonition of a longitudinal wave?
A longitudinal wave has vibration that are parallel to the energy transfer, this causes rarfraction and compressions
what type of wave is light?
a transerve wave
What is the deffonition of a transverse wave?
a transverse wave has vibrations that are perpendicular to the energy transfer, this causes peaks and troughts
what is frequency of waves
How many waves per second
measure: Heartz (Hz)
what is a wave
a wave transferes energy from one place to another without any overall transfer of matter
how is a wave created
something needs to vibrate, a collection of partciles or an electromagnetic field
what is the definition of frequency and what is the unit
the frequency of a wave is the number of vibrations per second (Hz Hertz)
what is the definition of a time period
time period is the time for one vibration (s seconds)
what is the definition of amplitude
the amplitude is the maximum displacement of a vibration from its rest position
what is the definition of wavelength
the distance from a point on a wave to the same point on the next wave (peak to peak) (m metres)
what is the relationship between time period and frequency
time period = 1/ frequency
what is wave speed
the speed at which energy is transfered through the medium
how do you measure the speed of sound in air
- one person stands a large distance away from person two and make a loud, visible noise
- the distace between them should be measured with a tape measure
- person 2 starts the clock when they see the sound being made and stop the clock when they hear the sound
- speed calculated by
speed = distance / time
what is the relationship between wave speed, frequency and wavelength
wave speed = frequency x wavelength
how can you measure the speed of ripples on water surface
using a ripple tank, use a ruler and then divide by 10 to find one wavelength, you can read the frequency from the signal generator
speed = frequency x wavelength
what is the difference between diffuse and specular reflection
- specular reflections happens when light is incident on smooth surfaces, they are parralel rays f incident light relfected ina perpendicular manner and remain parralel.
- diffuse reflection happens on rough surfaces, parralel rays of light do not remain paralell to each other and are scattered in different directions
what is refraction
refractinon is the change in speed of a wave when it reaches the boundary between two different materials
why does refraction happen
it happens because materials have different optical densities, this cuses the wave to change direction
what happens to frequency and wavelength when a wave undergoes refratction
when a wave undergoes refraction its frequency dosent change, thi is becaue the source of the wave dosent change at all.
- is a wave refracts because it speeds up the wavelength increases
- if a wave refracts becuase it slows down the wavelength will decrease
what effect does the refraction of light lead do
refraction of light at water / air causes objects to appear closer to the water surface than they actualy are
what are electromagnetic waves
electromagnetic waves are transverse waves that transfer enegry from the source of the waves to an absorber
what are the waves in the elctromagnetic spectrum
long wavelength, low frequency
- radio waves
- microwaves
- infrared
- visible light
- ultraviolet
- x-rays
- gamma rays
short wavelength, high frequency
what are the comon uses for the waves in the elctromagnetic spectrum
- radio waves: broadcasting and comunications
- microwaves: cooking and comunications
- infrared: heaters, night vision, remote controls
- visible light: we use it to see
- ultraviolet: flourescent lamps
- x-rays: medical equipment
- gamma rays: sterilising food and medical equipment
what are the hazards of the waves in the electromagnetic spectrum
over-exposure to certin types of electromagnetic radiation can be harmfull, the higher the frequency of the radiation, the more damage it is likely to cause to the body
