Waves Flashcards
What is a wave
a transfer of energy from one place to another without the transferof matter
what is the substance energy passes through called
the meidium
what is equilibrium position
where particles are normally found when no energy is passing through the medium
what do we see as a wave
The viabration of particles in medium
how do particles vibrate in a transverse wave
perpendicular
what are crests and troughs
Highest and lowest points of particles vibration
examples of transverse wave
Light, earthquake s waves
how do particles vibrate in logitudinal waves
paralell to the direction of motion
what are compressions and rarefactions
where particles are close together ,where particles spread far apart
logitudinal wave examples
sound waves,earthquake p waves
what is amplitude
maximum displacement of particles from equilibrium position
is amplitude the same in both directions
yes vibration is symetrical
what is wavelength
distance between two succesive particles undergoing same motion
what is period
time taken for one complete wave to pass a point measured in seconds
what is frequency
the number of complete waves that pass a point per second measured in hertz (Hz)
what is wave speed
how fast energy travels through a medium
what is reflection
when waves hit a surface and bounce off
how does an echo form
when sound waves are reflected by large hard surfaces the reflected sound can be heard as an echo
what is a ray
an arrow drawn representing the direction in which energy is being transferred in a wave
where does energy go in reflection
-some bounces off
- some enters the medium
when a wave is reflected what decreases
the amplitude
where is the normal
90 degrees from the surface
where are angles of incidince/reflection measured
between ray + the normal
what is the law of reflection
angle of incidence=angle of reflection
how do reflected rays travel
smooth level surface=regular paralell reflection, uneven surfae- difuse reflection ( range if directions)
what is a plane mirror
flat mirror
what happens when light reflects off a plane mirror
an image of the original object is formed in the mirror- same size same distance inverted
what is refraction
the change of speed of a wave as it enters a new medium
what direction will a slowing down wave turn
bend towards the normal
what direction will a speeding down wave turn
bend away from the normal
does water waves travel faster in deep water or shallow
deep water
what is optical density
the speed of light in a transparent medium
what does the value of the refractive index tell you
the higher the value the slow waves travel
what are the units for refractive index
there is none but the symbol is n
refractive index in air =
1
snells law is?
when light travels fro air to another medium
n=sin I divided by sin r
