What is Reflection: Definition and 953 Discussions
Reflection is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves. The law of reflection says that for specular reflection the angle at which the wave is incident on the surface equals the angle at which it is reflected. Mirrors exhibit specular reflection.
In acoustics, reflection causes echoes and is used in sonar. In geology, it is important in the study of seismic waves. Reflection is observed with surface waves in bodies of water. Reflection is observed with many types of electromagnetic wave, besides visible light. Reflection of VHF and higher frequencies is important for radio transmission and for radar. Even hard X-rays and gamma rays can be reflected at shallow angles with special "grazing" mirrors.
Homework Statement
We begin by considering the forces exerted on a ring that is connected to a spring and that is free to slide along a rod
TOP VIEW: The diagram is top view
Diagram Description (sorry don't have a pic): A pulse traveling towards a free end (has NOT reached the boundary...
I wasn't sure where to post this and i apologize if its already been posted. I think there is an obvious answer for this but for some reason I cannot figure out a consistent answer. I am looking for a mathematical answer more than anything else. When you look in a mirror you image is switched...
Homework Statement
Two copper wires, one 1.0 mm in diameter and 1.0 m long, the other 2.0 mm in diameter
and 2.0 m long, are joined together end-to-end and hung vertically. In order to tension
this compound wire, a block is suspended from it. It is found that a transverse pulse takes
50...
We use only 2 boundary conditions in driving Fresnel's laws, whereas Maxwell's equations provided 4 conditions (2 were identical to other 2). What is the intuitive explanation for this redundancy? which boundary conditions turned out to be equivanlent to each other.
Regarding "Total Internal Reflection"
Hi, and thanks in advance for viewing this post.
I'd like to type out the question first;
Q: Consider the optical interface between crown glass and ethanol.
a) Under what conditions would total internal reflection be possible at this interface?
Illustrate...
1. How does scientists know that the light from far distant heavenly bodies are actually from those, or some kind of reflection?
2. If a red object reflects only red frequency light, why I do not see red light from that object to the surrounding?
Homework Statement
When a beam of monochromatic x-rays is incident on a particular NaCl crystal, Bragg reflection in the first order (ie w/ m=1) occurs at theta=20 degrees. The value of d = .28nm. What is the minimum voltage at which the x-ray tube can be operating?
Homework Equations...
As I know, a black substance absorbs all light and a white substance reflects all light.
Can I say, in a black substance, the electrons are in a high energy state, compared to a white substance?
And how much light energy it can absorb? There has to be a limit to it, right?
So, shouldn't a...
I once heard a very interesting thought through a zen story, that said "Nature reflects the true self." So simple, yet I had felt that before, but didn't know how to explain so crispe and clear. Now, the problem for me comes with the question not doubting this thought, since we have our own...
"Reflection of an Integer"
I haven't encountered this before. I'm not sure how to approach it. At this point it's not even clear to me why the result should only be divisible by one number in *every* case.
The reflection of a positive integer is obtained by reversing its
digits. For...
How does light reflect? I am going to speculate below and maybe one of you all who have more experience in Physics can tell me if I am correct or give me a reference. I have an undergraduate degree in EE so you can talk to me as someone with a little college physics but (obviously by what I am...
https://www.physicsforums.com/showpost.php?p=899393&postcount=4 describes why photons are slower in some medium. After reading it, I've few more questions:
When a photon hits an electron, if it absorbs the photon and reemits, here's my questions:
1. How does refraction possible?
The...
Why does light reflect?
I know that it does, and the rules and uses connected with this, but WHY does the em wave actually change direction on hitting a shiny surface? Is it at an atomic level?
Cheers
Tom H
Hey!
When a photon is reflected off an interface doesn't it deliver some of it's momentum to the object that it hits due to radiation pressure? If so, shouldn't the reflected light have a longer wavelength (smaller wavenumber) than the incident light? Is this effect present, but just so small...
heres a simple question I somehow couldn't find an answer on the internet.
we know radio waves only reflect (significantly) when it strikes an object with size greater than the wavelength, but I'm not sure what exactly defines the "size" of the object.
For example, if I were to confine a...
light refractions problem
I don't even know where to start with this problem. Can someone please help me out?
As shown in Figure P22.49, a light ray is incident normal to on one face of a 30°-60°-90° block of zircon(n= 1.923) that is immersed in water.
Figure P22.49
(a) Determine the...
Hello,
I'm trying to understand how exactly light changes its polarization when reflected from a mirror, for example.
I'm quite familiar with Fresnel's equations and resulting coefficients, but I'm not sure how the phase of the TE and TM polarizations changes upon reflection.
For example...
I noticed that when my lamp reflects off of my HDTV, it appears red. It seems that the more light that is reflected into it, the redder it gets. I'm figuring that the green and blue line of the phosphor dots (I think that's the name for the tiny red, green, and blue lines on a screen) are not...
We know that if M is an orthogonal matrix,then DetM=(+-)1
When Det M=1,thee transformation is a rotation.And for reflection about anyone o all three axes DetM=-1.
I did this..
But I did not know that information:When Det M=1,thee transformation is a rotation.And for reflection about anyone...
in solving the time-dependent Schrödinger's equation for the delta potential, one obtain a set of non-normalizable solutions.
form the boundary condition and comparing the coefficients of the solution, one obtains the probability of transmission and reflection.
However, how can one be sure...
Hello, I am wondering how does a reflection diffraction grating work. Most physics text simply ignore this topic or talk in very ambigious terms. I understand that in transmission diffraction grating, you have parallel grooves so that light can pass through and produce an interference pattern...
Homework Statement
The refractive index of the Earth's atmosphere is:
n=1.01+(alpha)(R-r)
where (alpha) is a constant, r is radial distance from Earth's centre and R is the Earth's radius. By considering a path comprising a series of total internal reflections or otherwise, find a value of...
Homework Statement
1. Dubbie is moving directly along a normal line toward a plain mirror at a speed of 3.5 m/s, what is the speed of the image relative to Dubbie?
2. What is the speed of the image, relative to Dubbie, if Dubbie walk away from the mirror surface at 3.5 m/s at an angle of 300...
As the angle of incidence increases, the angle of refraction becomes larger.
Should the underlined word be decreases? why? I think I've found a mistake in the book because according to snell's law of refraction n1sin(theta)1=n2 sin(theta)2 right? If n1>n2 then (theta)1<(theta)2
Wait, I...
While making calculations of FTIR/tunneling isn't that hard, I don't understand the phenomenon, and therefore there are some predictions I'm unable to make. So I have some questions (or it's probably just one).
If you have a prism with refractive index n in vacuum, total internal reflection...
Homework Statement
You stand 1.80 m in front of a wall and gaze downward at a small vertical mirror mounted on it. In this mirror you can see the reflection of your shoes. If your eyes are 1.95 m above your feet, through what angle should the mirror be tilted for you to see your eyes...
Homework Statement
Having done an experiment measuring the intensity of light reflected from copper, lead, zinc and iron, i found that copper reflected the most light, then iron, then zinc, then lead.
Now i have to explain it and I don't really know how to !
The Attempt at a Solution...
Homework Statement
A person stands 3.6m in front of a wall that is covered floor to ceiling with a plane mirror. His eyes are 1.8m above the floor. He holds a flashlight between his feet and manages to point it at the mirror. At what angel of incidence must the light strike the mirror so...
when a mechanical wave is reflected by a fixed support it experiences a phase change of pi ... without getting into maths can i qualitatively prove this ? i cannot analyse how the forces will be acting .
Why does a wave reflect when it meets an impedance discontinuity? And why is there a 180 degrees phase shift of the reflected wave when the transmission line finished with short circuit and no phase shift when the far end of the line is opened?
Homework Statement
In the case of total internal reflection, show that the average rate of energy transport across the boundary is zero.
Homework Equations
None Provided
The Attempt at a Solution
All that I have come to is that I should use some form of the following method to find...
Homework Statement
An alkali halide is studied with the Debye-Scherrer technique and Cu K_{\alpha} radiation. The Bragg angles for the first five lines (in degrees) are 10.83, 15.39, 18.99, 22.07, and 24.84. Calculate
(a) The lattice parameter
(b) The Miller indices for the planes producing...
Hi there,
I am new member to this forum.
I am taking online courses, in order to get my degree.
For all of the problems, the transmission line in the problem has a characteristic impedance of 50 ohms and is one quarter wavelength (an electrical length of 90 degrees) at the frequency of the...
I was thinking... When you shine a light in a mirror, the surface is reflective enough to produce a smooth image. Are we reflections of light, or does light simply shine on us to light us up? It would seem like when light hits mass, it is reflected, which produces the images that we see. And if...
Homework Statement
The reflecting surfaces of two parallel mirrors are facing each other. They are placed 10cm apart. A light source is placed in middle of the two mirrors. Calculate the distance of the 3rd reflection from the original point source in both the mirrors.
Please tell me how...
Homework Statement
Okay, I've got a question that's been bugging me for the longest time.
I've got a string attached to a wall at one end (the other end is free to move, though) and it has a sinusoidal wave traveling to the right and hits the wall at x = L and reflects. I'm supposed to...
Homework Statement
A thin 1.00x10^-5 cm-thick film of MgF2 (n=1.38) is used to coat a camera lens. Are there any wavelengths in visible spectrum intensified in reflected light?
Homework Equations
thickness = wavelength/4n (n is refraction index)
?
The Attempt at a Solution
I am...
We have 1 particle.
Classical Mechanics says: If I know the initial state I can predict with absolute certainty what position (etc.) it will have the next second.
Quantum Mechanics says: I don't know the position the particle will hit. But If I know the state I can tell you the possible future...
Homework Statement
The point Q is the reflection of P(-1,3,4), in the plane with equation 2x-y+z=1.
Determine the coordinates of Q
Homework Equations
The Attempt at a Solution
Well I am not really looking for a solution. I just want to know what I am trying to find. What is a reflection in...
From what I have been reading, the reflection of light from an object, like th eyellow color of sulfur is the same phenomenon as Rayleigh scattering. It seems that the electrons receive the incoming photon and are raised to a higher "virtual energy state." When they return to the ground state...
How do the angle of incidence relate mathematically with the angle of reflection after the critical angle, that is, in a TIR?
Say we have a person standing at the bottom of a swimming pool, if we take the n for water as 1.33 and for air as 1, we get the critical angle of 48.75 degrees. When the...
hi, i got a real problem. i have a question here and have absolut no clue what i have to do and which equation i have to use...
( for my shame, i was sick at that time we done it in school..)
question:
A diver is at the bottom of a lake, which is 10m deep. if he looks straight up he...
Homework Statement
I have a transparent plate (call the thickness t and refractive index n), it has a scratch at a point A. A microscope objective (M, positive) images the point A in A' at a distance D from the objective. If we move M a certain distance d down (without changing focus, meaning...
Homework Statement
Consider an infinitely long continuous string with tension \tau. A mass M is attached to the string at x=0. If a wave train with velocity \frac{\omega}{k} is incident from the left, show that reflection and transmission occur at x=0 and that the coefficients R and T are...
Two submarines are underwater and approaching each other head-on. Sub A has a speed of 12 m/s and sub B has a speed of 17 m/s. Sub A sends out a 1520 Hz sonar wave that travels at a speed of 1522 m/s.
... I already solved for this question ...
... What is the frequency of the sound detected by...
qw: A photon is incident on a beam-splitter. At high light intensities, the beam-splitter is known to transmit 30% of the incident light, and reflects 70% of the incident light. Calculate the probability that the photon is refected, and the probability that the photon is transmitted.
how do i...
Consider the step potential defined by
V(x) = 0 if x < 0
Vb > 0 if x=> 0
a) Compute te relfection and tranmission coefficients for a particle of energy E > Vb approaching from th left
For x < 0
Schrodinger equaion since V = 0
-\frac{\hbar^2}{2m} \frac{\partial^2 \psi}{\partial x^2}...
In Figure 33-48a, a light ray in a liquid (n = 1.61) is incident at angle 1 on a boundary with an underlying material, into which some of the light refracts. There are two choices of underlying material. For each, the angle of refraction 2 versus the incident angle 1 is given in Figure 33-48b...