Ray Definition and 493 Threads

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...

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...

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...

Hello Guys! Please help me in this question: What is the nature of the gamma ray bursts? Why do they last for mo only 2 seconds? thx!

I am not sure if the universe ever expanded at speed inferior to that of light, but if it did, I am curious to know what would have happened (if it didn't happen) if a light ray (or any electromagnetic wave that is) had hit the boundary of the universe?

Homework Statement I have to find out a relationship between the deflection of an electron beam in a cathode ray tube and the accelerating voltage. Homework Equations I know that theoretically D is inversely proportional to the accelerating voltage. The Attempt at a Solution I have to...

Is there anybody out there that can help me?? Ok in a TV set, the electrons that are emitted come from the heating filament. Now as i read on this site...the heating filament replenishes its stock of electrons from an AC supply. I understand that bit. So there is an AC supply of electrons to...

Will all objects melt and burned if a high energy ray like gamma ray is shined unto it? My guess is no, since gamma photons will be absorbed by the objects if the photon energy is the same as the transition levels in the object. If it doesn't, then the photons will not be absorbed, and just...

When an electron and anti-electron come together a gamma ray is produced. So are gamma ray bursts just the product of lots of electrons and anti-electrons coming together? I gather that at least twice the mass of our Sun is required for a gamma ray burster to form,so if we have two masses and...

Hi! I know these cosmic ray flux rates on Earth: 10^{16} eV: the arrival rate is one particle per square meter per year. 10^{19} eV: the arrival rate is one particle per square kilometer per year. 10^{20} eV: the arrival rate is one particle per square kilometer per century. What are...

- the Flying Manta Ray :cool: :cool: :cool: http://www.youtube.com/watch?v=HBa9wdOANHw&mode=related&search=

Hey sum1 please tell me that : if d1=Ray of light through a glass slab(dotted line ie extension of unrefracted ray) and if d2=Refracted ray is d1/d2=mu(refractive index)

Why is the end of the hot filament where negatively charged electrons are being fired called the cathode end. 'cat' in chemistry means positive, I assume the same goes in physics as well?

Hi, I did a homework problem in which I was to show that a refracting telescope, modeled as a sequence of two thin lenses separated by a distance equal to the sum of their focal lengths, is capable of producing angular magnification. In my course we have been solving these questions in...

Homework Statement For an optical microscope, complete a ray diagram for an objective lens and relate the relate the relative distances to the lens equations. If you want to increase the magnification, should the objective lens have a shorted or longer focal length (illustrate this on the same...

Homework Statement The problem is: The left end of a long glass rod 10.0 cm in diameter, with an index of refraction 1.5, is ground and polished to a convex hemispherical surface with a radius of 5.0cm. An object in the form of an arrow 2.00mm tall, at right angles to the axis of the rod, is...

I'm hopelessly stuck on this question. Any help will be greatly appreciated. Prove that if we have a parabolic mirror with focus at F and axis of symmetry the x-axis, then a light ray emmited from F will be reflected parallel to the x-axis. To prove this consider the parabola y^2=4px (where...

Here is the problem I am working on: Sunlight enters a room at an angle of theta = 32° above the horizontal and reflects from a small mirror lying flat on the floor. The reflected light forms a spot on a wall that is d = 1.9 m behind the mirror, as shown in Figure 26-42. If you now place a...

HELP-HOMEWORK...Hi, I have homework that ask "Using the velocity of light find an approximate value for the amount of time that it takes a light ray to travel from the sun to the earth." Now I know the distance between the Earth and the sun is 93 million miles but I'm not catching on to the...

For a course in Experimental Aerdynamics I have to study a section on Optical Measurement Techniques. My oral exam is coming up and there is this little thing I don't understand. It annoys me expremely. It is the ray equation. It is about light ray path in a medium with changing refractive...

hi all, may be my problem is a simple one. I want to calculate the intensity field resulted due to a UV lamp in side glss cylinder located at a distance from the lamp. The lamp is sorrunded 3 sides by reflectors such that 90% of the light power is reflected. now i have to calculate the...

Sir, Two plane mirrors M1 and M2 have a length of 2 meters each and are 10 cm apart. A ray of light is incident on one end of mirror M2 at an angle of 30 degrees. What is the number of reflections light undergoes before reaching the other end? I solved it in the following way: In each...

Pioneering physical chemist and physics Nobel laureate Ray Davis has died at his home in New York. Davis, who spent most of his career at the Brookhaven National Laboratory, shared the 2002 Nobel Prize for Physics for his contributions to neutrino astrophysics. He passed away on Wednesday aged...