Ray Definition and 517 Threads

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?

Homework Statement An electron is accelerated horizontally from rest in a television picture tube by a potential difference of 5710 V. It then passes between two horizontal plates 6.45 cm long and 1.24 cm apart that have a potential difference of 249 V (see figure below). At what angle q...

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."...

Multi-Lens System Ray Tracing --Please help Homework Statement It isn't possible to form an image of a real object on a screen with only diverging lens. However, if we use a converging lens, it is possible to create what is called a virtual object. The diverging lens has a virtual object...

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...

Ray Tracing...HELP! Homework Statement An object is 6.3 cm from a convex mirror with a focal length of 10 cm. Use ray tracing to determine the location of its image. Homework Equations The Attempt at a Solution 1/f = 1/s + 1/s' 1/f - 1/s = 1/s' 1/10 - 1/6.3 = -0.0587 cm ^ -1 =...

So I have an array p(t) = e + td, where e is the start position, t is some parameter, and d is the direction of the ray For a sphere with center c and radius R, the vector form equation is (p-c).(p-c)-R^2=0 This can be algebraically manipulated into: t = (-d.(e-c) +- sqrt((d.(e-c))^2 -...

If the exploding star that caused the gamma ray burst on Wednesday had occurred as close to us as Alpha Centauri what would be the effect on Earth?

Surrounding the planets usually exists the various atmosphere. Due to this atmosphere, one light ray crossing the planet will be refracted more if it comes more closely to the planet's surface. So how to know that " gravity field phenomenon is the curved light ray" is not created by the planets'...

I saw in a website that Einstein found the deflection angle of a ray grazing the sun through this relation alpha=4GM/c2r=1.74 arc sec but when i used this relation by giving values i didnt get this value 1.74...wats wrong..can anyone solve this ...

Homework Statement A person 1.62 m tall wants to be able to see her full image in a plane. a) What must be the minimum height of the mirror? b) How far above the floor should it be placed, assuming that the top of the person's head is 15 cm above her eye level? Draw a ray diagram...

Prism Entry and Exit How does the angle at which a ray of light strikes a prism compare with the angle at which it passes out the other side? I think its the same...?

Ok, so this is probably a really basic question, and I've got a feeling that my brain is just too 'fuzzy' just now and that all my problem is is simple arithmetic, but here it goes... 1. Determine whether or not the box with vertices at (2,1), (5,1), (5,5), and (2,5) is intersected by the...

Do darker colored clothes offer more protection, or do light colored clothes offer more protection? I have found many answers in both.

Homework Statement An electron in a cathode ray tube is accelerated through a potential difference of ΔV = 11 kV, then passes through the d = 4 cm wide region of uniform magnetic field. What field strength (in mT) will deflect the electron by 10(degrees)? (Hint: is it a reasonable...

Homework Statement Find the frequency and wavelength of a 100 MeV gamma ray photon Homework Equations 100 MeV=1.602 X 10^-11 The Attempt at a Solution I do not know how to do this. I am in a class for elementary teachers and we have to solve this problem.

Does a gamma ray ray carry enough information to prove its source?

[SOLVED] Cosmic Ray Protons Homework Statement Earth's atmosphere is constantly being bombarded with cosmic ray protons that originate somewhere in space. If the protons all pass through the atmosphere, each square meter of Earth's surface would intercept protons at at the average rate of...

[SOLVED] Cathode Ray - No Electric Field Homework Statement Consider J. J. Thomson’s 2nd experiment, the discovery of the electron. Turn on a magnetic field, but turn off the electric field. If the electrons enter a region of uniform magnetic field B and length l, show that the electrons...

Can somebody please explain what actually happens in cathode ray tube? Is there any current passing through the tube? How does the anode (positive electrode) lost electrons? Is it before the effect of cathode rays? How does the cathode (negative electrode) have bigger amount of electrons? Is it...

On February 1, 2007, the Konus-Wind, Integral, Messenger, and Swift gamma-ray satellites measured a short but intense outburst of energetic gamma rays originating in the direction of M31, the Andromeda galaxy, located 2.5 million light-years away. The majority of such short (less than two...

hi i was wondering about the russian helicopter death ray and if it was based on the russian multi beam klystrons and all in one technology. does it use tesla multi beam technology? thanks

Caveat 1: I'm not sure if this message should be posted here, or in the Programming forum. Caveat 2: I have a BS in Physics, obtained more than a decade ago, but never actually worked in the field. So I'm a bit rusty. :redface: OK, more than a bit. I am writing a program to simulate the...

I need some help with the 2 lens inverted ray diagram. Like i need someone to describe to me what it looks like or could show me an example of 1. thxn

Next month I am going to be teaching my 9th grade "Physics First" classes about optics, and I'd like to use a set of lasers to show them how rays diverge and converge in various situations. Students will literally be able to see things like this...

Homework Statement I'm have a little problem with understanding the workings of a cathode ray tube. I understand that a filament is heated and that in turn heats the cathode which, due to thermionic emission emits electrons. OK so here is my problem. A positively charged anode is used to...

Hey guys having a bit of problem with my year 1 essay. Would really appreciate any help :) What are the main sources of gamma ray bursts both short and long duration? I know some are from supernovae but where do others come from?

A 1.0 cm high object is situated 11.0 cm in front of a concave mirror that has a radius of curvature of 8.00 cm. Using a ray diagram drawn to scale (the mirror must be drawn to scale): (a) measure the location of the image: 6cm (infront of the mirror) (b) measure the...

Hi, this is the question in my homework. Explain what happens when a light ray enters and leaves a glass block if it hits the face of the block at right angles to it. Can someone pelase help me, i think that the light ray would just go straight through the block without bending but I am...

I was watching a show on Discovery about things that could end the Earth and one of them was a Gamma Ray Burst. They said on the show that by the time we knew it was coming towards us, it would be too late but if it moves a the speed of light or slower wouldn't that mean that we would see the...

If the motion of an electron creats a magnetic field around it then why is an electron beam in a cathode ray tube deflected at right angles and not towards the magnetic field? Also, what would be the effect of a magnetic field on a stationary (relative to the field)electron?

Cosmic Ray Muon Production Altitude is not right! Hi there, I wrote a Programm to calculate the cosmic ray muon intensity on different altitudes. I dedicated this programm from the intensity of the primary cosmic rays and the intercations in the atmosphere. First a Proton with the Energy...

ive been researching cosmic rays, and came across this question that i can't quite work out. can anyone help? what is a cosmic ray proton of Etot 10^9 Gev, collides head on with a low energy photon from remnant 3K balck body radiation in the universe. if the photon has energy kT, can we work...

Hey guys I'm new here and I'm lookin' for some help as I'm sure a lot of you come here for that reason as well. I did an experiment where I fill a 150 mL half full, place a pencil in the middle and move it sideways until it reaches the side of the beaker. Then I am to draw a ray diagram of what...

1. Find the crystal structure , the lattice parameter of the metal. Known 2\theta of the peaks 17 21 28 33 35 41 45 46 2. bragg's law \lambda=2 d_{h,k,l} /b]sin^{2}(\theta) Also, the cubic interplanes distance d_{h,k,l} = a0/(squr(h^{2}+k^{2}+l^{2}) [b]3. The Attempt at a Solution ...

I recently finished reading the book "The singularity is near" by Ray Kurzweil, in which he tries to predict the development of technology over the next decades and the impact this development will have on society. Based on the accelerating nature of technological evolution, Kurzwail claims that...

Here's a question on ray optics. We say that the focal length of a lens is half times the radius of curvature, right. Now, consider any lens(say convex), made of any material(say glass). Now a beam of light parallel to the principle axis, passes through the lens. All the rays in the beam will...