common properties of waves Flashcards
what type of waves can be reflected, diffracted, refracted
ALL WAVES CAN
how is an echo heard from sound waves
When the sound waves from a source hit a wall, the waves are reflected back towards the source, and when the returning waves reach the original source, echo is heard.
what happens to wavelength when any wave is reflected
wavelength stays the same
define wavefronts
wavefronts are lines of constant phase, such as crests.
what does the distance between wavefronts represent
the wavelengths
When does refraction occur
when wave moves from one material to another
does water or glass have higher optical density
glass has higher optical density
what can you say about the materials when light is refracted
the materials have different optical densities
What 3 things can be observed when a wave refracts
the wave will change its speed
there may be a change in direction
wavelength also changes
how does a optician help a person see better with the glasses.
and how does the glasses work
glasses refract light, and the optician refracts the light by specific amount so that it is focussed on the retina.
Light comes through the concave lens
light is then refracted to the eye lens
then light refracts again from eye lens onto the retina to form an image on retina.
How to investigate refraction and reflection in a ripple tank
The ripple tank is a shallow tray of water. And in the water is a vibrating bar.
The bar is connected to a power pack. When the bar vibrates, it creates waves across the surface of the water.
We have a lamp above the ripple tank, and a white sheet of paper below it.
When light shines through the paper, it produces an image of the waves on the paper.
We then take a picture of the sheet of paper with a ruler aligned beside it.
We then measure the distance between one wave and 10 waves further, so total of 10 wavelengths.
To find one wavelength, divide the value by 10.
To find the frequency, place a timer next to the paper and count the number of waves for 10 seconds. Then divide that number by 10 to get the frequency
Define diffraction
Its the spreading out of a wave after passing around an obstacle or through a gap.
when is diffraction most pronounced
when the wavelength of the wave being diffracted is the same size as the gap that they are travelling through.
