Reflection Of Waves Flashcards
Waves have 3/4 choices on what to do when they hit an object (depending on how you look at it). What are they?
They could either be absorbed, be reflected, be transmitted with which sometimes leads to refraction
Waves have 3/4 choices on what to do when they hit a boundary. What does a different outcome depend on?
What they do when they hit a boundary (absorb, transmit, reflect, refract), depends on the wavelength of the wave that hits the boundary and the property of the material which the boundary belongs to
What happens when a wave is absorbed?
Waves are absorbed when the wave arrive at a boundary it’s trying to cross into. When the wave hits the boundary, the action transfers the energy of the wave to the material’s energy store. The wave gives up the energy so doesn’t come out of the object (transmission)
What happens when a wave is transmitted?
The wave is transmitted when it keeps on travelling; into the material and back out. Often, when it comes back out, the wave is refracted.
What is the one law of reflection?
I = R which stands for the angle of incidence equals the angle of reflection. Always.
Where can we find the angle of incidence?
It’s always located between the normal and incoming ray
Where can you find the angle of reflection?
The angle of reflection is between the reflected ray and the normal line
What does the normal line look like?
It’s an imaginary line that’s perpendicular to the surface of the point of incidence. The normal is shown as a dotted line
Where is the point of incidence?
It’s where the incoming ray hit the boundary of the material and where the reflected ray is coming out from
There are two types of reflections. What are they?
A diffuse reflection and a speculate reflection
What’s a specular reflection like?
When a wave hits a smooth surface (like a mirror) and is reflected in a single direction
What is a diffuse reflection like? Why does it happen?
When a wave hits a rough surface (like paper) and all the waves are reflected in all kinds of diff. directions. This happens because the normal line is at a different angle and place for each incoming ray
True or false: because diffuse reflects are so unruly, they break the rule of I = R
False, this rule still applies. Although the normal line is different for all the rays altogether, there is still a straight normal for each of them.
What will a specular reflection look like?
A clear image
What will a diffuse reflection look like?
A blurry/unclear/incomplete at a stretch image
