Ray Definition and 493 Threads

I've two questions here:- 1) Sound reflects it is said using laws of reflection of light.So,it means we hear max. sound when angle of incidence is equal to angle of reflection,right?& if not equal then what do we hear or not? I guess we hear lesser than max.sound when the angles are not equal...

Homework Statement If you were given 4 cookies, each emitter different ray 1)Alpha, 2)Beta,3) Gamma , 4)neutron You have to make decision of the following: a)eat one of the cookies b)dispose one of the cookies at storage facility called WHIP c)put one of the cookies in your pocket...

the unit of cosmic ray flux is expressed as flux /(m^2.sr.s.GeV), so what does sr stand for? Thanks.

Homework Statement One of the thermonuclear or fusion reactions that takes place inside a star such as our Sun is the production of helium-3 (3He, with two protons and one neutron) and a gamma ray (high-energy photon, denoted by the lowercase Greek letter gamma, ) in a collision between a...

Homework Statement In an old TV cathode ray tube, electrons are accelerated by a potential of 15 kV between the gun and screen. Find: a) Kinetic energy of the electrons when they reach the screen b) Its respective wavelength c) Wavelength of the photons with maximum energy that are...

I'm not sure if this thread fits into this particular forum, but about how many megatons would be equal to the explosive power of a gamma ray burst?

hey there, I'm interested in (eventually) simulating light ray paths near black holes, starting with schwarzschild black holes and working my way to kerr-newman black holes. I have a good understanding of the nature of black holes but have trouble when it comes to the equations. My background...

A) In a cathode ray tube, electrons are accelerated from rest by a constant electric force of magnitude 6.22 x 10−17 N during the first 2.00 cm of tube's length; then they move at essentially constant velocity another 46.5 cm before hitting the screen. Find the speed of the electrons when they...

"When a wavefront of X-rays strikes an atom, the electrons in that atom interact with the X-rays and immediately re-emit the X-radiation, normally without change of wavelength, and the X-radiation that is emitted by the atom is emitted as a spherical wavefront " Now my question is : visible...

When I look at a nuclear level scheme, there are many gamma ray transitions from energy levels of say, spin 4 to spin 2. However, my understanding was that photons carry spin 1, and so conservation of angular momentum would say that you can only change the spin of a level by 1. What am I missing...

I learned from a website that cathode ray tubes fire electrons from an "electron gun" at the cathode towards the anode, hitting a piece of metal and produce cathode rays in the process. My question is; how do cathode tubes "shoot" electrons? Apparently it's due to a high potential difference...

Hi.I wonder is it possible to create a home made muon or gamma ray detector? And if it is possible would you mind to show me some way? Thanks...

I don't want to hijack another thread, so I'm moving the discussion here... A point about Archimedes Death Ray came up. The question is whether it failed for practical or theoretical reasons. I am of the opinion that it failed for practical reasons due to the inability of a bunch of...

Homework Statement If the apex angle of a prism is f = 74.3° (see figure below), http://i32.photobucket.com/albums/d2/NikkiNik88/apex.gif what is the minimum incident angle for a ray if it is to emerge from the opposite side (i.e., not be totally internally reflected), given n = 1.55...

Could someone please check my work and provide insight on what I may be missing to complete the problem. The question's from Ray Serway's Physics For Scientists & Engineers 4th Ed. Vol. 1. Chapter 4. Review Problem #1. Page 95. Homework Statement A ball is thrown with an initial...

Homework Statement An object is 6.0 cm in front of a converging lens with a focal length of 10 cm. Use ray tracing to determine the location of the image. Is the image upright or inverted? Is it real or virtual? The Attempt at a Solution According to my ray tracing...there is no...

Homework Statement A light ray enters the atmosphere of a planet where it descends to the surface 15.2 km below. The index of refraction where the light enters the atmosphere is 1.2 and it increases uniformly to the surface where it has a value of 1.55. I) How long does it take the ray...

I just can't comprehend that gamma ray can come out of a black hole. Gamma rays are electromagnetism which contain photons, but photons have no mass. And we all know that a black hole swoops up light as well. And what recaton has the gamma ray on the mass around the black hole? I know It's true...

Hey everyone, I need to be able to be able to explain how a gamma spectrometer (NaI scintillator) can determine the energy of a given gamma ray (or more particularly, determines the effective dose rate, but that shouldn't be to hard once I figure out how to get the energy). The problem, as far...

From what i have read the gamma ray frequency cap ranges from 3×10^19 to 3×10^24. I want to know what you guys have heard it is. Are the highest measured gamma ray from a supernova calculated with any time dialated effects? Also what is the thoertical cap of something higher than a gamma ray...

I found two different descriptions about ray transfer martix of interface in two textbook. I am confused about this. which one is correct? I hope someone can help me. _________________________________________________________________ A:Lasers, A.E.Siegman,pp586 B:Laser Resonators and Beam...

Homework Statement The figure from the link below shows a cross section of a cathode ray tube. An electron in the tube initially moves horizontally in the plane of the cross section at a speed of 2.0 x 107 meters per second. The electron is deflected upward by a magnetic field that has a...

Homework Statement When an object is located very far away from a convex mirror, the image of the object is 18 cm behind the mirror. Using a ray diagram drawn to scale determine where the image is located when the object is placed 9.0 cm in front of this mirror. Note that the mirror must be...

Hi all, Does the antenna gain depend on the angle of the emerging ray? or It can be a single number for all ray emerging in all directions? I know the gain is the amount of power an antenna has relative to an isotropic antenna. Sometimes it means the maximum power an antenna can have relative...

Hello, I'm attempting to analyse the data recovered from an experiment that I performed in lab, but I'm having some problems understanding how to properly apply the statistical methods learned to this specific problem. Essentially, the experiment consisted of placing a source of gamma rays...

¿Why one cannot push light but just in the normal direction to the ray? NAIVE QUESTION: I understand I cannot push a light ray (I mean, to sum speed vectors) in its propagation path, but ¿why I can certainly push it in the normal direction to the light ray? Is there some info on this...

Homework Statement A 4.0m wide swimming pool is filled to the top. The bottom of the pool becomes completely shaded in the afternoon when the sun is 20 degrees above the horizon. How deep is the pool? Homework Equations \theta = arcsin(n2/n1) n1sin\theta1= n2sin\theta2 The...

Homework Statement A light ray leaves point A in the figure, reflects from the mirror, and reaches point B. (Intro 1 figure) figure attached How far below the top edge does the ray strike the mirror? Homework Equations The Attempt at a Solution im not sure exactly where it...

Is anyone familiar with the "y n u" ray trace method for optical systems, using paraxial rays where Snell's law is approximated using: n1sinx1 ≈ n1tanx1 ≈ n1u1 = n2u2 If anyone is familiar with this, I'd be interested to discuss the finer points of "a-ray" and "b-ray" tracing, as well...

Homework Statement The figure shows a meter stick lying on the bottom of a 100-cm-long tank with its zero mark against the left edge. You look into the tank at a 30^\circ angle, with your line of sight just grazing the upper left edge of the tank. 1)What mark do you see on the meter stick...

How do the photons actually interact with the atoms to make them diffract. is it related to de broglies equation some how? Also with High energy electron diffraction, are the electrons being diffracted because they are attracted and repelled electrostatically from the nucleus and orbiting...

Homework Statement A primary cosmic ray (which comes from elsewhere in our Galaxy) hits the nucleus of an atom in our atmosphere 38 km above the ground and creates an unstable secondary particle, which then travels straight down toward the ground at a speed of 0.99400c. (The altitude and the...

Homework Statement A ray of light strikes the midpoint of one face of an equiangular (60◦, 60◦, 60◦) glass prism (n = 1.3) at an angle of incidence of 33◦. a.Trace the path of the light ray through the glass, and find the angle of refraction at the first surface. b.Find the angle of...

Okay, I'm writing a short response of about one page right now. Here's the question: Regarding soft gamma ray repeaters, 1. Is there any connection between the electromagnetic radiation and gravitational radiation? (specify: luminosity of the source? Thresholds?) and 2. How much...

3) X-rays of wavelentgh 0.010nm are directed onto a target containing loosely bound electrons. For Compton scattering from one of those electrons, at an angle of 180 degrees, what are a) the Compton shift, b) the corresponding change in photon energy, c) the kinetic energy of the...

I was reading this: https://www.physicsforums.com/showthread.php?t=181830 I was wondering if there is any up to day info about the speed of gamma ray burst that could confirm or debunk these claims. Or are LQG and String Theory in troubles?

http://www.sciencedaily.com/releases/2008/09/080919185809.htm * "This is the most amazing burst Swift has seen," said the mission's lead scientist Neil Gehrels at NASA's Goddard Space Flight Center in Greenbelt, Md. "It's coming to us from near the edge of the visible universe."...

Simple Ray Optics Problem--Check my answer? Homework Statement You're helping with an experiment in which a vertical cylinder will rotate about its axis by a very small angle. You need to devise a way to measure this angle. You decide to use what is called an optical lever. You begin by...

Very cool image. Does anyone know, is anything in the information we got from this so far at all surprising? Is it likely we will learn anything about gamma ray bursts from this or is more information

In gamma-ray spectrometry with germanium detector, the summing effects have to be taken into account at low source detector distance. The peaks due to coincidence summing of X+X, X+gamma, gamma+gamma rays can complicate the spectrum obtained by this type of detector and significantly change the...

Hi, Atmospheric gamma-ray extensive air showers are induced by pair-production interactions. The equation that governs pair production is: \gamma + \gamma = e^- + e^+ My understanding of the interaction is that a gamma passes "close" to the electric field of a nucleus. The nucleus acts...

Consider a ray at the interface air and glass (n = 1.5). We know that incident angle i and refracted angle r are related by sin i = 1.5 sin r Can we some how show the relationship between i and r is r = m i + c (straight line)? If you look at the following data, it follows the Snell's...

questions about life of gamma ray particle question-are gamma ray particles unchanged after gamma ray burst 13 billion years ago? question-are changes detected not due to travel through normal space, scattering? changes due to dark matter/energy? question-positronium decay at end universe...

I can't seem to get my head around refraction so on this thread I will ask many questions to understand the concept (bit by bit). These two questions to start of with. Could someone help me with them? When a ray is traveling from air to water, does it refract away or toward the normal? Is...

Homework Statement A positively charged particle of mass 7.2 * 10^-8kg is traveling east with speed of 85 m/s. The particle enters a 0.31 T uniform magnetic field, and 2.2 * 10^-3 secounds later leaves the field one-quarter south with speed of 85 m/s. What is the charge of the particle and...

cosmological principle states that, on large spatial scales, universe is homogeneous and isotropic. in other words, universe looks the same in every direction and that is true for every point of view. there are some challanges to this principle, but for this discussion, I will assume it is...

I'm considering dissecting an old, color cathode ray tube television. Do cathode ray tube televisions have capicitors in them that could shock me?

Homework Statement A light ray is incident on a prism whose apex angle is 65.0°. The ray is incident at θa and leaves the prism with θa = θd. The refractive index of the prism glass is 1.54. Calculate θ ans:55.8° Homework Equations n1sin\phi1=n2sin\phi2 The Attempt at a...

http://web.mit.edu/2.009/www/experiments/deathray/10_ArchimedesResult.html

Homework Statement a) A back-of-the-envelope calculation shows that in about 120 seconds the gamma ray burst released a total energy of about 10^48 Joule. How does this compare to the total energy that would be released by instantly vaporizing our sun into pure energy? (The sun's mass is...