Physics

I would call it applied chemistry or inorganic chemistry more than physics because there is no study in the physical behaviour of the matter but on the composition of the matter...

In church the other day my friend and I were thinking of something profound. Taking physics for a long time I thought I would find a logical answer. We were thinking about something. If there was a hole trough the earth and someone jumped in, what would happen? Would they fall through and land on the other side? Would they fall through and continue into the sky towards space on the other side? Would they fall through and get halfway and be stuck in the middle of the magnetic pull (like the earth has gravity going one way for each degree of it and they would be stuck in the middle of them all)? I chose the latter of the choices due to an "educated guess". Does anyo…

Hi, We made an experiment in class where we measured the evolution of temperature over the course of 5 weeks. I'd like to show that the increase in temperature is accelerating as summer is coming. Is it enough to calculate the slope of the linear trend over the full 5 weeks and show that it is smaller than the slope of the linear trend over the past week (increase in trends) to deduce that it is accelerating ? I'm asking because my teacher said that comparing linear trends over different time periods is not always appropriate and can be biased, but i don't understand why. Thanks.

do anyone think that time has a speed and if its broken than things will go faster and why.

ok.. simple question... I am asking for help. does anyone know how to isolate, EASILY.. CHEAPLY.. the isotopes of mercury??? I seek and desire Hg 196... which naturally.. is .15% of all naturally occuring mercury. Any thoughts??? -Mosheh Thezion

I am creating a coil gun using a capacitor bank consisting of 3 470uF capacitors rated for 500V. They charge to about 250V using a Cockroft -Walton voltage multiplier. A switch controls the amount the capacitors are charged and a voltmeter gives and accurate reading of the current voltage of across the capacitors. An SCR is in place to control the triggering of the gun, but is being shorted at the moment to test. The coil specs are Inductance = 0.673mH, Resistance=1.3 Ohms, 412 turns, 4 layers of 103 turns, 22 gauge magnet wire, turn density of 14.8 turns/cm, wrapped around a copper pipe. I tried firing a bb and it didn't even move. I'm assuming there isn't enough current…

I have prepared a draft about Stochastic scientific quantities and states. It includes the usual material (variances, medians, fluctuations, correlations), but I have added material which is not discussed in usual statistical physics literature, such as the stochastic Schrödinger equation. I have included an important remark by NG van Kampen about misconceptions regarding the concept of ensemble and some other criticism. If you find some mistake let me know. Criticism and suggestions are welcomed.

In agreement with one administrator I am posting this here. The topic is multidisciplinary but my main doubts are for physicists. I have just uploaded a draft about Open, closed, and isolated systems. I am using the standard terminology, although, in the discussion section, I notice that some physicists use a coarse-grained terminology. I suppose that their terminology is motivated by their lack of interest in problems of chemical or biological interest. I do not recommend the use of this coarse-grained terminology, because I do not find any reason for using it. If someone disagree, please state your views. I also criticize the textbook by physicists Walter Gr…

hey guys what is the entropy change in an adiabatic reversible process. i thought its 0 as U=W+Q and for an adiabatic process Q and W are 0. thanks guys

i am looking to order some super-strength magnets, but i am confused by something it says on one product it says: '26kg pull (South)' and on another, otherwise identical product, it says: '26kg pull (North)' what is the difference between these two magnets? surely they both have a north and a south pole...?

I don't know what these bowls are made of except that they are plastic but when they come out of the microwave, the bowl is hotter than the food. I thought I had read that microwaves are only absorbed by water and pass through or are reflected by other materials, which is why they penetrate the food and heat it evenly instead of from the outside inward as with conventional/infrared ovens.

If you were to throw some, lets say Volvic (other brands available) water into an ocean of Volvic water, would the water you have thrown in sink or float? I'm not a physicist, as you can probably tell. In fact, I'm not sure whether this should be in the physics or chemistry section, but I was just wondering. Thanks lol

A 60 year old mechanical engineer speaking (MSc etc etc). If space is expanding what is the opposite? You get nothing for nothing therefore a 'force' must be created for every cubic metre of space that is being created as the universe expands. Fair enough, but this means each cubic metre of space in the universe contains some sort of force that was required to create it during the original expansion? Answers in less than 1000 words please.

I know that it is a mixture of layers of glass and a polycarbonate, and obviously the more layers the greater the bullet resistance. And that you need a lot of heat and pressure to bond the layers together, what else is there to know?

When someone tosses an object into the air, the trajectory is a parabola as I have learned in Physics. But why do planets follow ellipses? I ask this since both the object and planets are being pulled by gravitational force.

Thinking about convection currents. If you had a closed-loop of pipe full of liquid, in the shape of a square, stood it uupright, and then heated the left vertical side whilst cooling the right vertical side, would the liquid flow in a clockwise direction? Rising in the left side and sinking in the right etc? If not, could it be made to do so by maaking some kind of adjustments to the set up?

In definition of matter, it comes that matter is one, which occupies space, and have the mass. Matter occupy space, meant, what ? Which are the things, do not occupy the space? (In definition of matter, is there any necessity of saying that matter is one which occupy the space ?) Why the two matters do not occupy same place, at same time ? (please try to answer by avoiding of pauli exclusion, if necessary include this too)

The Question (Submitted November 05, 1997) I would like to know why the moon turned red during a recent lunar eclipse? The Answer: When you saw the moon turn red, it was because the light that was hitting the moon, from the Sun, had to go through the Earth'satmosphere. The atmosphere scatters blue light more than red light (why the sky is blue) and so what comes out the other side is red (why sunsets are red).This reddish light bounces off the moon, comes back to Earth and goes into youreyes. By: Jonathan Keohane for Ask an Astrophysicist My Thoughts On This: if that were true then the northern lights t…

I was reading articles, when I came upon this "riding a bicycle is safe." from an article on Noether's theorem, What I don't understand, is how was that riding a bicycle is safe concluded, and what is Noether's theorem ?

Hello,my Nam is Nobel in Nigeria.i have very little knowledge of circuit.i need help to make a helpful but simple project for my school for a competition.i want to be simple and cheap.

The factory-installed radio in my car does not work. So I purchased from Radio Shack a palm size battery-operated radio. There is a favorite radio station which I like to listen to by keeping the radio on the passenger seat when I am driving the car alone. The problem is that when I tune in for that station, I get quite a bit of interference --hissing sound-- which more or less disappears (and I am able to listen to the station quite well) if I either hold the radio in my palm or even place my palm about six inches away from the radio. Needless to say that this solution is useless while I am driving the car. As a possible alternative solution to improve the radio's se…

Imagine a house in a cold climate, where the conventional insulating outer wall is divided into thinner less insulating concentric layers with habitable spaces between them. The inner core has a heat source and the highest temperature, and accommodates activities with a high comfort temperature as relaxing, laying down etc. The following layers have room for more strenuous activities where a lower temperature is tolerated. As I understand it, heat loss is less when the difference in temperatures is smaller. Is less heat lost to the environment due to the comparably low temperature in the outer layers? Will this system reduce the heating needs for the house in general…

I was just asked this looking trivial question ... and honestly it doesn't look so simple. Atom is just a bunch of particles hold mainly by electromagnetic interactions - doesn't pure Coulomb repulsion tell that some electrons should immediately run away? Would e.g. F- or Cl- atom be stable while just flying in empty vacuum? How stable? My first answer is the magnetic attraction between oppositely directed magnets - electron couples? But the distance between them seems to be too large for such attraction (1/r^4) ... however there are suggestions that magnetic conjugation still works on larger distance, like for Cooper pairs or that neutral positronium scatters like…

Do you think that dynamics as a whole can be unified?

I have recently purchased neodynium magnets and they are very powerful for their size. It got me wondering, what makes a magnet magnetic? Also, what makes something magnetic (eg. a paper clip)? Lastly, I was wondering what makes a mirror so reflective? Could it be that there is a tight pack of electron that are deflecting the photons and so acting like a mirror? Thanks