Effects Definition and 1000 Threads

What exactly in the photoelectric and Compton effects can't be explained with the wave model of radiation? For instance in the photoelectric effect, why the fact that the energy of the electrons emited from a material after being subjected to certain radiation depends only on the frequency of...

Homework Statement What effects occur on a conductor within a circuit, for example copper wires - what can effect them and what can be done to control the effect? Homework Equations None The Attempt at a Solution I have no real understanding of electrics but one attempt is...

Hello, I'm designing for a rotating swivel assembly that will be used for a high pressure cutting system. The rotary swivel is set for an allowable 2800 bar of pressure but has to rotate at 300 RPM while allowing a pressure of 12-15,000 psi pass through it. My question consists of two...

Does a mass in rotation exert a different effect gravitationally than the same mass at rest? I recall it does. As a thought experiment can we take a dense, small mass and place it in extreme rotation so that it's effect on the local gravational field is intensified? This thought experiment...

i wanted to say hi and i have a couple questions. I'm letting everyone know that i have the electrical understanding of a basic beginner. first question: what are the effects of a voltage multiplier on amperage? second question: is there an amperage multiplier? thanks.

The famous double-slit-experiment has been widely discussed just about everywhere, but I'm wondering about seeing wave-particle duality with a single-slit experiment. This experiment would consist of a source of particles, a screen with a single slit, and a second screen with some sort of...

Hi there... My question is that when nucleon's loses energy (such as in fusion),does that affect their size as well? do they also shrink or grow by losing or gaining energy?

Hi all! I'm doing a statistical mechanics class this semester where very often questions like "consider the limit of temperature going to..." pop up. Now, if you consider a relativistic system (say some gas), to what extent does it make sense to talk about temperature going to 0? [to me...

Hey, I was wondering what were would happen to the fluid flow or if this would cause any structural problems to the following case. A vertical pipe of 150mm diameter and roughly 3 metres in length is at the bottom of a large tank. At the bottom of the pipe is a coupling which leads to...

I know someone whose life has been badly affected because his father is a drunkard. That is one the reasons I'm against alcohol because I've seen it with my own eyes how it affects others' lives. There are too many accidents because people drive while drunk. Many other crimes also stem out of...

Maybe this should be posted in biology but it seems more like an electricity question to me: I've read that static electricity increases in the cold because of lower relative humidity. This seems to mean that it is more difficult for things to dissipate/ground their electric charge to the...

hi, I am confused about how the vapor pressure affects the materials growth. Can someone comment on the following : If the vapor pressure of a precursor, let's say N, is high then it will be hard to grow a material containing N because it will be hard to incorporate it onto the substrate...

Hi, To understand the difference between uniform magnetic fields and field gradients would it help to make comparisons between their effects on different particles? The posts on Stern-Gelach shed some light here. For instance, what effect would a homogeneous and an inhomogeneous magnetic field...

Diffraction is obviously a limiting constraint on high-precision imaging instruments. But is it possible, given a known aperture shape, to remove the diffraction caused by that aperture? At this point, I know that the diffraction pattern of an aperture or slide film brought to rear focus is...

Questions Polonium-210 has a half life of 138.4 days. It decays to stable Pb-206 by emitting an alpha particle with a kinetic energy of 5.31 MeV. Alpha radiation of this energy has a relative biological effectiveness of 20. a) If the difference in mass of Po-210 and Pb-206 nuclei is...

Questions Polonium-210 has a half life of 138.4 days. It decays to stable Pb-206 by emitting an alpha particle with a kinetic energy of 5.31 MeV. Alpha radiation of this energy has a relative biological effectiveness of 20. a) If the difference in mass of Po-210 and Pb-206 nuclei is 4.00731u...

hi, let's suppose 2 electrons are far away each other and therefore they interact very weakly. i wonder if in such case there are as many virtual photons in the case they are very close to each other? because i know that only 1 electron in complete vacuum generates an electromagnetic field and...

Here's my issue. We will say that from our reference Object A is stationary and Object B is moving. Object A witnesses Object B traveling 6/7 the speed of light, thus Object B's "onboard clock" is running half as fast as Object A's, though it appears normal to Object B. If Object B does...

At what length scale do quantum effects become important in gravitational calculations??

If there weren't hills,mountains etc, (that means purely spherical earth). And suppose we weren't told Earth was round. When we walk , we would think we are walking in never ending football ground(infinitely large playground ). Isn't this the effect of so called general relativity effect...

Homework Statement Hello i just have an interesting question, and was wondering if my answer to it had any validity. Ok so i did an experiment The Current balance experiment(for everyone not familiar with it, you can google it and get all the info you want) to try and estimate mu naught...

Hi! I'm a biologist so be easy on me:) Say I had a one liter glass flask filled with air and I had a 100 psi air compressor attached to it. (I don't want to suck air out but blow more inside!) How would the air in this flask react - according to the law of ideal gas the temperature of the air...

Homework Statement a) The share of American spending on Canadian goods is about 80% of Canadian exports, which are themsevles equal to about 45% of GDP. What is the share of American spending on Canadian goods relative to Canadian GDP? b)Assume the multiplier in Canada is 2 and that a...

Homework Statement A small solid sphere of mass M0, of radius R0, and of uniform density ρ0 is placed in a large bowl containing water. It floats and the level of the water in the dish is L. Given the information below, determine the possible effects on the water level L, (R-Rises, F-Falls...

Responses from physicians, scientists, or PF members sought and welcomed.

i know that motion of source can change the frequency of wave. constant speed motion will not change the wave progagation relative to water itself.but from the point of a observer at speed 0, the propagation speed will change. so my question is what will happen to frequency? thanks for help...

Hi. The higher the velocity of an object the more energy this object has. Velocity is purely relative. When I move I might *** well consider that I am still but all of my surroundings move. So if I travel with a velocity near the speed of light matter and radiation should appear more...

If time requires movement in space time in order for change and hence time to occur then how does absolute zero in temperature effect time since no molecular or atomic movement is possible at such temperature? Does vibration constitute movement that can affect time in relativistic terms? Is it...

So, I'm working through some ideas dealing with Lagrange points. I understand that, the rotation and mass of 2 objects in space create stable areas where an object of "insignificant Mass" compared to the objects it's balancing against, allows for the placement of an object in a stable area...

Assume we have a non rigid ball. When this ball is radially free falling in a Schwarzschild metric the height increases while the width decreases due to tidal effects. How do we calculate the ruler width and height in terms of R and m? When we have two of those balls radially free falling...

How could i reduce the effect of diffusion of ions in an electrolysis cell. e.g AgNO3 Ag+ Stirring constanly would help? but that's not easily kept fair or constant. Could i replace this idea with rotating electrodes? Many Thanks, Adam

Homework Statement Here is an interesting reading to my question. http://coraifeartaigh.wordpress.com/2010/02/27/what-is-a-field/ The author wrote: The reason he said each charge will experience a different force is assuming different r (and not a constant r)? Another question is to...

Homework Statement I was asked by my lab teacher to investigate the effects on the human body of being exposed to very high and very low pressures, and while I have found some good sources of info it is not that easy to find good and quotable sources, I was wondering if anyone could offer some...

Can you please suggest me some books to read on this topic? It's for my final year project! I would much appreciate it!

is the light doppler effect a purely relativistic effect? or it is present even in the classical limit?

Hi there. As a molecular biologist my knowledge of physics is fairly limited to the topics I learned before college, but recently I have developed an interest in learning a bit more about it. More to the point a certain question has been puzzling me for some time now and I was wondering if...

In my attempt to obliterate my ignorance I'd like to discuss something related to the recent news story about a young man who attached two clamps to his nipples and then had a friend plug it into a wall socket. http://news.gather.com/viewArticle.action?articleId=281474978486647" <-- News Story...

Velocity through an orifice follows a certain equation until the fluid approaches the speed of sound; magnetic fields obey certain equations until the magnetic material becomes 'saturated'; gasses obey the ideal gas law until the gasses atoms become too close to each other. There are many...

I live in an area where the water supply has a very high amount of lime, what if any thing doe's this do to ones insides.

If a gas is enclosed in an insulated container on earth, I understand that at the top of the container there will be less pressure than at the bottom due to gravity. What I want to know is if the top is colder due to the effects of gravity. If reliable sources could provided it would be...

While observing the Sun, which is 8 light-minutes 12 light-seconds away from us. We (by visible and invisible spectrum of the electromagnetic radiation) observe its state 8.20 minutes ago. Special relativity forbids any information to travel at speeds greater than that of light. This should...

I know that Caffeine gives a boost in the amount of Beta-Waves in the brain, but what does it do to the Synchronicity of brainwaves between the 2 Hemispheres? It's well known that a brain with higher synchronicity is more efficient than a brain with uneven brainwave synchronicity... Since...

I'm very unfamiliar with energy-use in aviation, but I am wondering about what effect altitude has on parameters such as gravity (i.e. weight of the aircraft) and air-density, which I would think affects friction and combustion as well as lift. One thought I've had is that higher velocities...

Hi all, Can anyone brief some history and the Characteristics of SiC diode. I having difficulties to find the infomation about the SiC material. Beside that, how the Temparature related with the I-V curve (Eg: 200k, room temp,600k) and different between the Si and SiC at room temp? Thx.

Homework Statement a uniform rule has a mass of 90g and its centre of mass is at the 50cm mark. the ruler is suspended by a thread at the 70cm mark, balanced by a mass of weight W hanging from the 80cm mark. Calculate the moment of the weight of the ruler about the 70cm mark. What is the...

I've noticed a number of threads asking about sleep paralysis, and especially loud noises when falling asleep. I found this article and thought others might be interested. http://www.livescience.com/health/sleep-disorders-top10-100208-1.html The "loud noises" is a disorder called...

What are the known or suggested effects of γ-radiation on carbon 60?

When James Cameron made Titanic in 1997 it touched the hearts of people all around the world. I was a kid at that time knowing not much about love, pain, loss of loved ones, injustice around us, it still stands as one of my favorites; and it is always a new experience each time I see it. Rarely...

This study presents evidence that the complex endogenous (internal) electric field generated by the activity of individual cortical neurons exerts a feedback which has a global modulating effect. The linked summary links to the full article (PDF). (The second link is a bit slow as this is a long...

I was trying to read up on the effects of the Lorentz transforms on electromagnetic fields in the stationary and moving frames and came across the following equation for the E-field: [1] E= \frac {Q}{4 \pi \epsilon_0 r^2}* \frac {1- \beta^2}{(1- \beta^2 sin^2 \theta) ^{3/2}} The first...