Reflection Definition and 966 Threads

(Not Spam :-p) I did a bit of reading today on partial reflection when using ultrasound. I was reading about a pregnancy gel that is applied to the womans stomach when detecting a baby. To put it briefly, if the ultrasound transmitter is held away from the body a lot of energy is reflected...

I am having trouble understanding this idea, I will quote what I have read and then post an image. This is not a homework question if anyone asks, it is an extension of what I am doing at school, but I would like to do some work through my week off. :-p "Waves that are incident on solid...

This promises to be a very difficult final vote since all the pictures that made it this far are outstanding. Please vote for the picture that best represents our theme, which is a reflection of an image. 1. Chi Meson 2. larkspur 3. fi...

This is the second group in this contest. You have one vote. Please vote for the picture that best represents our theme. 1. Janus http://home.earthlink.net/~parvey/sitebuildercontent/sitebuilderpictures/reflect.jpg 2. Mech_Engineer 3. fi...

This could be a brutal voting process. There are many outstanding pictures in this contest. The pictures are in 2 different voting threads, so you have 1 vote for each group. Please vote for the picture that best represents our theme, which is to depict a reflection. 1. Chi Meson 2...

what happens with the atoms, while there is reflection of light? What happens with the electrons or protons, are they reflecting the light and how?

A Moment Of Reflection Our theme this week is on pictures that includes images that have been reflected. The images can be reflected off mirrors, water, smooth surfaces, etc. However, please note that the pictures must show clearly that what we're seeing is a reflection, especially when it is...

Homework Statement Look at the diagram. Draw the wavefronts as they would appear after the reflection. Draw and identify the following things on the diagram. Incident ray Normal Reflected ray Angle of Incidence Angle of reflection Homework Equations n/a The Attempt at a...

I am having a friendly argument with a friend. If a light source was moving towards a colored object at high speeds in a completely dark area, would the color shift due to the Doppler effect be doubled? Possible theories are no (which we agree is wrong) Yes (which may be right) Or simply...

If one is trying to reduce Earth mean temperature, why not cover it with aluminum foil? :D

[b]1. A white light source is below the lower surface of a piece of optical-quality glass. The glass has an index of refraction of 1.520 for red light and 1.538 for violet. If you were able to move your eye at any angle relative to the perpendicular to the glass, calculate A) Which color...

Question: At the bottom of a glas bath lies a mirror covered by 20cm of water.In the air,30 cm above the water there hangs a lamp.Find the distance from the mirror at which an observer looking into the water will see the image of the lamp in the mirror Relevant Formula: apparent shift...

Homework Statement In an amusement park maze with all the walls covered with mirrors, Pilar sees Hernando's reflection from a series of three mirrors. If the reflected angle from mirror 3 is 52° for the mirror arrangement shown in the figure, in which = 12°, what is the angle of incidence on...

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...

If reflection of light is an interaction with atoms how we get always angle i=angle r?

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 http://img244.imageshack.us/img244/6852/phys24xy.png Homework Equations d=1/N d*sin(theta)=m*(lambda) The Attempt at a Solution d=1/1970 d=.0005076 .0005076*sin(theta)=2*600e-9 sin(theta)=.0000012/.0005076 arcsin(.002364)=.135º *sigh*

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...