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
Given the sphere (x-2)^2+(y-1)^2+(z-1)^2=4 and the plane x+2*y+2*z=15, find the
equation of that sphere which is the mirror image of the given sphere relative to
the given plane.
The Attempt at a Solution
I was thinking the following
constraint #1: eq. of...
I've been asking myself this question that is not entirely clear to me: the Bragg condition used to describe the constructive interference of waves on a crystal is based on the assumption of reflection. However, x-rays diffract on a crystal rather than reflect, so theoretically there is always...
Consider i m moving at a velocity considerable to the speed of light. Above me there is a mirror stretching to infinity . It doesn't move with me. Now if i shine light on the mirror where will the reflected beam hit me?right on me, back of me or infront of me?
I have the following "Parabolic Dish" z=c(x^2+y^2)
I have to prove that all the reflecting light rays that hit that dish go through the same point Q in the Z axis, and then I have to find said point Q.
I've thought of reducing the problem to 2 dimensions. Started with the parabola y =...
Hello everyone, I am new to this forum, and to physics really, so i apologize in advance for silly mistakes.
Bascially, I am a keen A-level student, and i spend much of my spare time reading and trying to learn physics, far above me, it would be fair to say, I've jumped in at the deep end...
Looking around at all the cheap surplus beam splitter cubes out there. I've found no description of how things would be expected to behave outside of the spectral bands for which they're designed.
Leaving out the transmissivity of the glass itself, should I assume that when relative...
Homework Statement
I was asked to determin the film thickness for an oil film (n=1.33) for a light beam (500 nm) to give total reflection. I could calculate refraction angle for air to oil, but have no idea as to how to approach this question.
Homework Equations
The Attempt at a...
Homework Statement
I'm working through a step potential and I am confused as to why one of the coefficients doesn't go to zero.
V(x) = 0 when x < 0;
V(x) = V_not when x > 0;
a. Calculate reflection coefficient when E < V_not
I can solve the reflection part, it is a step towards it...
Homework Statement
As shown in the attachment, a radio signal travels down a tunnel, reflected by the walls and floor. Assuming that at most 2 hops contribute, calculate the voltage Vab at A due to current Ib in antenna B. Obtain a formula that depends on various parameters of the...
I'm not asking for what reflection and refraction are or the usual law governing it, but I would like to understand what they represent at the quantum atomic, molecular level? In a mirror is it about photons absorbed and emitted with the same wavelength and same direction through atomic electron...
I have been having trouble with this for a long time
1st - How and Why is a image formed ?
2nd - If all objects reflect light why is the image not seen on all the objects
Even walls reflect light but there is no image formation when light rays from an object reflect off an object and...
Homework Statement
X-rays of wavelength 0.09 nm are incident on a crystal. A reflected beam is observed at 36 degrees from the incident beam. What is the spacing of the planes in the crystal?
Homework Equations
Bragg's law:
2 d \ sin \theta = m \lambda
The Attempt at a Solution...
A tank whose bottom is a mirror is filled with water to a depth of 61.0 cm. A small fish floats motionless 21.0 cm under the surface of the water.
(a) What is the apparent depth of the fish when viewed at normal incidence?
(b) What is the apparent depth of the image of the fish when...
For a 3x3 orthogonal matrix with determinant= -1 (which means rotation followed by simple reflection), is the axis of rotation the same as the plane of reflection ?
My reasoning is follows (see attachment)
Say you have two vectors with the same angle size (which i call A), same x-values...
Hi,
When there is reflection, we generally use the phase shift upon reflection to be \pi. Where does this \pi come from or is it arbitrary? I ask because I came across an optics book which describes beam splitters (a mirror is of course a beam splitter with reflectivity, R=1 and...
Homework Statement
A lamp is placed in the center at the bottom of a 2m deep swimming pool. The lamp emits light in all directions. Starting from a point directly above the lamp, a man in a canoe paddles until he no longer can see the lamp. How far did he paddle the canoe? Assume that the...
Let's say there is a conducting plane of conductivity \sigma. Boundary conditions for above and below such plane are:
E_1^t = E_2^t
(D_2 - D_1 ) \cdot n = \rho
i.e. tangential components of E field are continuous and perpendicular components of D are discontinuous because of surface charge...
diamonds shine brightly because light inside them is reflected repeatedly within its walls.why this repeated reflection increase the brightness of light??
Hi,
I've this board, like shown in attachment, that has 2 rows. Each rows have 4 places. I'm trying to find a general function that gives me the reflection of the numbers.
I've 2 questions, so I put each question in a item.
a) Like shown in case a) of the attachment, If I write the...
Hi,
A wave is changing from medium A to medium B and it travels slower in medium B than in medium A. If I draw a normal line from the boundary to the wavefront the wavefront in medium B will move away from the normal? I attached to make it more clear
Furthermore, I got this question...
Hello everybody,
I've often read that if a light ray travels from a medium 1 to a medium 2 and the two media have the same impedance, there is no reflected light at all, only transmitted light.
So i made some calculations assuming to have two media with two different refractive indexes but same...
Just as the title says, suppose X is a symmetric manifold and \hat{S}(x) is the linear operator associated to \sigma_x\in G for some unitary irreducible representation,
where \sigma_x is the group element that performs reflections around x (remember X=G/H for H\subset G).
Now take the...
Reflection in a spherical mirror behaves like inversion in the sphere, which is the 3D equivalent to inversion in a circle.
2D Reflections in circles [i think, just play along] can be generalized to arbitrary 2D curves by finding the normal line(s) through the curve passing through the point we...
How Does Reflection Behave In Arbitrary Surfaces
Hi
I am interested to know how reflection would behave in a mirror on a surface of negative [gaussian] curvature.
I tried googleing it and found nothing useful
Thanks
Edit:
Reflection in a sphere behaves like inversion in a sphere...
Hello..
I just registered to ask this question which we were discussing with my friends for a while..
Why do you think the moonlight reflection on the sea is wider on the horizon once the moon is on the top, and the reflection goes narrower when the moon moves towards the horizon..?
We...
I've been curious about this question and hope that someone can provide a definitive answer with support for that answer.
Is it possible to directly see your own reflection in water?
From my understanding of reflections and my own observations I would say that it's not possible to...
The waves book by A.P.French gives two characterizations of the reflection coefficient for a 1-D traveling wave encountering an interface between two media. On one hand, he writes
R = \frac{v_2 - v_1}{v_2 + v_1}
where v_i are the wave speeds in the two media. Later on, he writes the reflection...
How do I determine what percentage of a signal is reflected and what percentage goes through a wall.
I know that I am over simplifying things, but for the purpose of my project I need a simple answer to this problem.
What parameters are needed for the solution and how do we calculate this...
Which of the following is consistent with experiment/observation.
When light is reflected off of a material, what happens to the photon?
A. Is it absorbed by the electron or lattice and then re-emitted?
OR
B. Does it somehow just reflect/bounce off the electron/lattice? Kind of...
Homework Statement
(Irodov - Problems in General Physics - 1-31)
A ball starts falling with zero initial velocity on a smooth inclined plane forming an angle α with the horizontal. Having fallen the distance h, the ball rebounds elastically off the inclined plane. At what distance from the...
If a photon is not absorbed by an atom during collision, what determines the direction of the reflected photon? Explicitly...
Does the photon reflect off of the valence probability 'shell' by abiding angle of incidence = angle of reflection? This seems counter-intuitive to me because some...
Hi,
I was about solving a refrection problem and I'm just one step away from the solution. I stuck at some simple problem I guess.
I have:
\alpha=60°+\frac1 3 arcsin(\frac1 {1,33} sin(\alpha))
and I want to find the alpha but I have troubles to solve this.
I guess it's not that...
A slotted line used on a 150ohm lossless transmission line connected to an unknown load impedance, ZL. The voltage standing wave ration is found to be equal to 3. The distance of the first voltage maximum from the load is found to be 9 cm, and the first voltage minimum is located at 3 cm from...
Homework Statement
A wave with the amplitude 4 cm travels along a rope that is fixed to a wall. The wave reflects from the wall. What is the amplitude of the reflected wave?
Homework Equations
I know it's something with light, could you explian in more detail?
The Attempt at a Solution
I'm going to be very careful to avoid the word "greenhouse" because of the indefinite ban on discussions about climate change - I want to be clear, this isn't a topic about that.
Part 1 - some gasses in the atmosphere absorb and emit radiation in the thermal infrared range. Gases like water...
reflection in a hollow metal waveguide...
Hello Forum,
when an electromagnetic wave hits a conducting surface there are surface currents generated on the surface itself. These currents are the result of the interaction between the field and the metal. Do these currents radiate their own...
Homework Statement
http://imgur.com/93CdT
Is the photo upside down?
Homework Equations
I do not understand the following:
- Why can the image of the sun in reflection not be higher above the horizon than as it is viewed directly?
- "What about the people in the photo? Try to draw a diagram...
In Griffiths Electrodynamics (page 397) electromagnetic wave reflection at a conducting surface is introduced. He says "for ohmic conductors, Jfree = sigma * E, there can be no free surface current since this would require an infinite electric field at the boundary."
I don't understand why...
So here's my problem... I have a particle traveling at velocity T, Vt, with components Velocity x, Velocity y, and Velocity z (3 dimensions).
This particle collides with a triangular surface. Each point of the triangle is known (x y and z for each point)
I would like to find the components...
A few days ago I started reading through Feynman's QED. It is a very good book, I am very much enjoying it.
There's something I don't understand. When Feynman starts to talk about why light is reflected such that the angle of incidence equals the angle of reflection, he gives an example where...
Homework Statement
If a light beam is circularly polarized and then bounced off a mirror perpendicular to the optical axis, what is the new polarization.
My thought is, because circularly polarized light has basically 2 components behaving like waves, each of them is going to experience a...
Homework Statement
An electron with kinetic energy 5 eV (8.01E-19 J) passes through a 3 eV (4.806E-19 J) potential barrier. There are certain widths for this potential barrier in which the transmission probability will equal one hundred percent and the reflection probability will equal zero...