Outside Definition and 459 Threads

Ok this makes sense but pressure inside an airway is determined by hydrostatic pressure and when air moves fast hydrostaic pressure is decreased and converted to kinetic energy. So this collapses the airway. My question is doesn't kinetic energy of moving molecules exert a pressure on the walls...

I'm trying to write a program to simulate the fields generated by a solenoid but I've hit a bit of a brick wall. There is a vast amount of examples and information on the field generated inside a solenoid however they all assume that the field outside is negligible and as such I have been having...

Hello all, I am a student in need of advice. I am a Physics and Applied Math senior at Humboldt State University in California, which I am confident will not open any doors. Over the next 3 months I will be applying for PhD programs in Materials Science, with the goal of obtaining a...

Homework Statement A chare +Q is distributed uniformly along the z axis from z=-a to z=+a. Find the multipole expansion. Homework Equations Here rho has been changed to lambda, which is just Q/2a and d^3r to dz. The Attempt at a Solution I have solved the problem correctly...

Does anyone know the proper way to do this?

I have a serious question to ask of anyone who can be of help. It is necessary that I say a few things about myself first so please read on I promise that this has to do with physics. Ever since I was 6 years old, I wanted to be a nature photographer. I worked for 7 years after high school as...

I just spotted another thread where the poster asked "can a modern scientist be religious". I thought about it and I realize that my crazy notions are some of my biggest motivators behind me aspiring to become a scientist. There could be unseen phenomena all around us that is yet to be...

I'm attempting to teach myself some electrostatics, so that I'll be prepared when I head back to school full time. Homework Statement Determine the electric field inside the inner conductor, between the conductors, and outside the conductors of a coaxial cable when the inner conductor is...

For neutron we all know, it has the 15 minutes of fame before it decays, what is the theoretical bound on proton's lifetime outside the nucleus, and to what it should it be dacayed to? As far as I can tell electron is a point particle and cannot be dissolved into other parts, are there any...

Homework Statement Find the volume of the solid that lies within the sphere x^2 + y^2 + z^2 = 16, above the xy plane, and outside the cone z = 3 \sqrt{{x^2+y^2}}. Homework Equations spherical system: x=\rhocos\thetasin\phi y=\rhosin\thetasin\phi z=\rhocos\phi cylindrical system x^2+y^2=r^2...

I'm not kidding. Two black vehicles, serious looking, and men in black suits are right outside. Should I post a pic or will that piss them off? Something's up. There aren't too many people in my apartment building, so they're probably here for me. Maybe. I've got to come up with something...

Homework Statement Find the electric field and potential inside and outside a hollow spherical shell (a \leq r \leq b) which carries a charge density proportional to the distance from the origin in the region, \rho=kr, for some constant k. Homework Equations The Attempt at a Solution I think...

Homework Statement A tightly wound solenoid of length L and radius a that has n turns of wire per unit length carries a current I. Calculate the the magnitude of the magnetic field at a point P on the axis of the solenoid, outside it and a distance y from one end, as shown in the figure...

The Universe is expanding. Expanding to where ? There must be an empty space where the universe will expand itself to, right ? Think about a baloon. Let's say the universe is everything inside the baloon. The baloon expands, because it has room to expand. If the universe is infinit, the empty...

If their was a suit that was able to stay hot on the outside of it, and you had no choice but to jump off an airplace that was about to crash and you were flying over the ocean. Would you be safe to jump into the ocean without breaking anybones because this suit was able to stay hot. I think...

Homework Statement A dielectric sphere of radius R has a uniform permanent polarisation P. Determine the electric field both inside and outside the sphere. (Hint: Since div P = 0 everywhere, the electrostatic potential satisfies Laplace's equation. Do not assume that the sphere is...

need help, I'm reading that W bosons are 80 GeV, but they are components of protons of ~1 GEV. Makes no sense. Is the 80 GeV the mass/energy of the particle if it is outside the proton? If so what is the mass/energy as a transfer particle within the proton. If you subtract the mass...

An outside observer will perceive my spaceship as being shorter, but what will i see of my outside surroundings? Will they be longer?

Homework Statement A conducting wire of length a and charge density lambda is embedded inside a dielectric cylinder of radius b. To Show: a) Bound charge on the outer surface is equal in magnitude to the bound charge inside the surface. b) volume density of bound charge is 0 in the...

Hello, I got a pratical problem; I want to know the gas temperature of SF6 gas inside a vessel. I can't insert a temperature probe to measure the temp. What i can do is clamp a temp. probe to the ouside of the vessel. Does this gives me a realistic reading, bare in mind the wetter...

Let's say it is 20 degrees Fahrenheit outside. If I have my thermostat set at 60 F, then each time my house dips below that temperature, my furnace should kick on and reheat it to 60 F. And the cycle continues... If I have my thermostat set at 68 F, then the scenario remains the same...

Homework Statement Find the potential outside a charged metal sphere(charge Q , radius R) placed in an otherwise uniform electric Field E0. Explain clearly where you are setting the zero of potential . Homework Equations The Attempt at a Solution At the boundaries of the sphere V=0. Since a...

1. An object is at rest at the TOP of the OUTSIDE of a loop. The radius of the loop is 10 cm. It begins to slide along the outside of the loop. It will obviously separate from the loop and then it lands x distance from the loop. What is x? 2. Equations of motion and conservation of energy...

[solved] Potential inside (and outside) a charged spherical shell Homework Statement Use the integral (i) to determine the potential V(x) both inside and outside a uniformly charge spherical surface, with total charge Q and radius R. Homework Equations (i) V(\vec{x}) =...

Homework Statement Determine the B field at a point P with distance d from centre of current ring radius r (d>r ie outside ring of current) but IN the Plane of ring (i.e off the axis) Homework Equations Biot savart: db=(u.I/4pi.r^2).dl.sinx u=mu, I=current, x=angle made with...

Does "mathematical reality lie outside us"? The mathematician G.H. Hardy 68 years ago expressed his belief that "mathematical reality lies outside us" in "[URL A mathematicians apology, p.35 [/URL]. I'd like to know how philosophers of the new Millennium have decided this question -- if at...

Dear guys, In GSW's string theory book, p.43, he derived and demonstrated the Ward identity. Start from the M-point function, A_{\mu_1m_2\cdots\mu_M}(k_1,k_2,\cdots,k_M) = \int d^4x_1\cdots d^4x_M\,e^{ik_i\cdot x_i}\,\left\langle T\big[J_{\mu_1}(x_1)J_{\mu_2}(x_2)\cdots...

Hello, I come from Belgium where I did my Master in Physics. However, in this country, with this diploma you can only teach in schools (ages 15-18)... PhD positions are relativelly few and far between. As I did not wanted to teach young poeple, I searched for a PhD outside my country and I...

Krauss, in his article in the Feb 2008 SciAm magazine stated: " Two different groups of astronomers traced the expansion of the universe over the past five billion years and found that it appears to be speeding up. The source of this cosmic antigravity is thought to be some new form of “dark...

I'm self teaching myself some physics. I enjoyed the subject in my undergrad Engineering days (~ten years ago) but didn't find we covered it thoroughly enough (more emphasis on calculation than understanding). Since I started my learning quest there have now been a number of times that I...

Homework Statement An insulated spherical shell with its center in the origin and radius R has a surface charge density of \sigma(\theta)=\sigma_0\sin(\theta) when \theta is the angle from the z axis. Calculate the electrical field outside the shell at point z=R. Homework Equations...

I was recently told that the temperature of a star (or flame, for that matter) is hotter outside the star than it is inside. This wascounter intuitive, since heat obviously disperses, so the hottest temperature seemed to be at the source of the heat in the center of the star. Are stars and...

Hi, I was hoping someone can verify this for me. In uni today we had to calculate the magnetic field of a ring of current, lying in the xy-plane. First we had to calculate it on the z-axis (perpendicular to the ring) which was easy. Then we had to calculate it on the y-axis (in the plane...

I will be graduating soon with a BSc as a physics major. I have done well in my physics program, but over the past couple years I have been continually losing interest in my physics studies. I do not want to do further studies in a physics program at graduate school. I was wondering if anyone...

In Algebra we are learning and using imaginary numbers. Someone asked if imaginary numbers are ever used outside of math, and our teacher said he talked to an electrical engineer who used imaginary numbers all the time. Our teacher didn't know how or why they were used in electrical...

With reference to this web page http://principles.ou.edu/earth_figure_gravity/index.html I calculate the force of gravity tangential to the long axis of a cylinder to be proportional to 4GM/R where M is the mass per unit length of the cylinder. Does that seem correct?

What do physicists think is outside the universe ( understanding the universe is finite)? More universes, quantum masch or something else? Please give your opinion.

Magnetic field outside a solenoid in 3D(off axis) Hey all, I am modeling an inductive proximity sensor and require the formula for the magnetic field just outside a solenoid off axis. In terms of a particle's position.i.e.(x,y,z). I have searched a lot of places. But most of the results show...

I ask this because it seems to me there is a striking paradox to a God's existence claim. I do think that what is and what isn't are conceptions that depend on our perception of the universe. So how, then, if we take down this road of thought, can we speak of existence outside the physical...

What does on do in an industry setting with a BS in physics? I really do no think I want to work IN physics. I suppose if I took some business classes I could end up alright. But what would a Physics BS look like to prospective employers? My goal is to be in a management position in...

Homework Statement During the action potential, Na+ ions move into the cell at a rate of about 2.98×10-7mol/m2/s. How much power must be produced by the active transport system to produce this flow against a +25.2 mV potential difference? Assume that the axon is 11.7cm long and 19.6um in...

So I have this question, and while I may not be in a position to apply it now, it is something I'm curious about. But for you guys who've already graduated and are engineers and have been for some time, how do you motivate yourself to keep learning? What sources do you utilize for these...

There's nothing wrong with this clock. So what's wrong with this clock?

Hi there. On my electromagnetism test there was the following question: A long solenoid with radius R has N turns per unit length and carries a current I = I_0*cos(ωt) Find the electric field inside and outside the solenoid. I got the following solutions: \vec{E} = \frac{\mu}{2} N...

If God exists outside of his own laws, the laws of science, then he exists outside of our reality, therefore he is not real. Claiming that you know God does or doesn't exist makes you moronic then, right?

I got as far as Calc 2 in college, took some college physics and read lots of popular cosmology books. What if I want to get technical now? What specific math do I need to know to fast track it without learning things that are irrelevant? It's too late to go back to school now.

Would entry be more likely if you applied to medical schools outside the United States?

If topology of a manifold were invariant (or not), what specifically would topology of a patch of such manifold in neighborhood (outside) of such BH, suggest?

Hi, Something weird happened the other week and I was wondering if anyone here could explain why. I run a pub and our cellar operates at about a steady 11°c all year round (cooler assisted). The other week we were enjoying some pleasant weather for the time of year(16/17°c) then wham! in the...

Hello all, sorry if this is a trivial question, or if it's been asked before, but I'm not good with math terminology so my googling doesn't give me much info.. I'm trying to work out a problem in order to recreate some functions that are missing from the public API of Google Earth. (If this is...