Waves Flashcards
What is the relationship for magnification?
m = di/do
On a plane mirror, what is the relationship between the angle of incidence and the reflected angle?
Θ1=Θ2
On a mirror/lens, the focal point is half of what?
The radius of curvature (r).
How is a real image created?
When two rays meet.
How is a virtual image created?
Lines are reflected in a way so they appear to meet.
What is the relationship between focal length, and image / object distance?
1/f = 1/di + 1/do
When does an image become virtual in a concave mirror?
When the object is past the focal point
Concave mirror: if a ray of light is parallel to the principle axis, where will it be reflected?
Through f
Concave mirror: if a ray of light travels through f, where will it be reflected?
Parallel to the principle axis
Concave mirror: if a ray of light travels through C, where will it be reflected?
Back through C
Concave mirror: if a ray of light hits the center of the mirror, at what angle will it be reflected?
At the angle of incidence (mirror acts like a plane mirror in the center).
If a virtual image is 2 cm behind the mirror, what value should you put into the lens equation?
Negative 2 cm (virtual quantities are negative)
Ignore with magnification
How would you describe the focal length of a convex mirror?
Virtual (it is behind the mirror, technically doesn’t exist)
Convex mirror: if a ray of light travels parallel to the principle axis, where will it be reflected?
As it it came from the virtual focal point.
Convex mirror: if a ray of light travels toward the virtual focal point, where will it be reflected?
Parallel to the principle axis.
If a ray hits the center of a convex mirror, what angle will it be reflected off at?
The same angle as the angle of incidence
If light enters a more optically dense substance, in which direction will it bend?
Toward the medium
If light enters a less optically dense substance, in which direction will it bend?
Away from the medium
How do you calculate the refractive index of something (i.e. what is the equation)?
Refractive index = speed of light in vacuum/speed of light in object
What is the primary relationship between angle and refractive index?
n1 sinΘ1 = n2 sinΘ2
What is the relationship between refractive index and light speed?
n1 v1 = n2 v2
What is the critical angle?
The angle at which a ray of light will experience total internal reflection
What is total internal reflection?
When a ray of light is not refracted, but is reflected back into the object
The critical angle can be seen as the point where the ray is reflected at 90 degrees (i.e. in the object). What is the formula for critical angle?
sinΘc= n2/n1
Convex lens: if a ray travels parallel to the principle axis, where will it be refracted to?
Through the focal point.
If a ray travels through the optical center of a lens, what will it’s path of travel be like?
Unchanged
Convex lens: if a ray travels toward the focal point, where will it be refracted?
Parallel to the principle axis
Concave lens: if a ray is traveling toward the focal point, where will it be refracted to?
Parallel to the principle axis.
Concave lens: if a ray is traveling parallel to the principle axis, where will it be refracted?
As if it came from the focal point on the other side of the lens
An image created by a concave lens is always…
diminished, upringht, and virtual
for a convex lens, objects past f create…
virtual images
What do waves transfer?
Energy (not matter)
What is the expression for the velocity of waves
v=f (lambda)
What is one attribute of a wave that never changes?
Frequency
In refraction, there is a “big relationship”. what is it?
n2/n1 = v1/v2 = lambda1/lambda2 = sinΘ1/sinΘ2
When is diffraction at it’s greatest extent?
When the gap equals the wavelength
Why does refraction occur?
Because one part of a wave hits the slower substance before the other, slightly changing it’s overall trajectory.
When a wave hits a boundary (like a change in medium), some energy is transmitted, while some is reflected. If a wave hits a thicker substance (in essence a fixed end), will the transmitted or reflected wave be inverted?
The transmitted wave will be uninverted, while the reflected wave will be inverted.
What is the name of the phenomenon when waves pass through each other?
Superposition
In interference patterns, what kind of interference do antinodal lines show?
Constructive interference
In the two-mouthed harbour example used to explain interference patterns, what is the relationship between distance traveled by each wave where the waves are strong?
The difference between distance traveled between the waves from the two sources is an integer of a whole wavelength, so they arrive in phase.
