Pole Definition and 368 Threads

Homework Statement A pole-vaulter leaves the ground with an upward speed of 9.5 m/s. (a) How fast is she going when she is 2.0 m above the launch point? (b) How long is required to reach this height? (c) Why are there two answers to (b)? The Attempt at a Solution Question A and...

in a text a read that " \oint \nabla A \cdot dl = 2 \pi n wich implies that the gradient of A has a pole singularity" why there is a singularity? I thing that this is a contidion to integral is nonzero but ¿what is the theorem used?

http://arxiv.org/abs/1307.5830 but its from gravitational lensing not primordial gravity waves so guess we are still waiting for those, but a good sign methinks.

I'm trying to run electricity from one side of the my land (country side) to the other. Electricity is 2000 feet away from light pole. first 500 feet I'm running number 8 wire. for the other 1500 I'm running number 12 wire. I'm getting a power drop because of distance. Local electricians told me...

T = N/A.m If T = 0.3249 N = 90N 90/0.3249 = 277.00 A.m Source. If not, can anyone please direct me on how I can calculate the pole strength, and magnetic moment too?!

Hi You'all, Newbie here so no calculus or polysyllabics on the first date please. If I hold a bicycle wheel horizontally and spin it at the north pole, the torque from the Earth spinning and the torque from the bicycle wheel are along the same axis. Does this mean the wheel could float off...

I'm reading the QFT textbook by Weinberg. In volume one chapter 10 page 451, at the lower part of the page he says, \Pi^*_{\mu\nu}(q) is the sum of all one-photon-irreducible graphs, with the two external photon propagators omitted, and q being the external photon momentum. Weinberg states it...

Homework Statement The magnetic field strength at the South Pole is around 66μT, and magnetic field lines point out of the Earth perpendicular to the surface. The sled is a metal square of side 0.95 m (with non-conducting wooden slats in between). What is the magnetic flux through the sled...

I read on Wikipedia (and verified myself) that if the beta function is proportional to the coupling raised to a power greater than 1, then there is a Landau pole, i.e., the coupling blows up at high energy. Here is what I got, for β=gα, where 1∠α, where g is the coupling and μ is scale...

The online edition of an italian newspaper, reported the curious event of a street pole which seems to vibrate for prolonged times, hours, even an entire day and without any clear reason. Someone talks about a building site in the nearby area, other talks about a wind turbulence called "vortex...

Homework Statement Question: Refer to Fig. 6-5. This standard TTL 2-input NAND gate uses ______ (open-collector, totem pole) outputs. Solution: The 2-input TTL NAND gate in Fig. 6-5 (which is attached as "TheFigure.jpg") uses a totem pole output configuration. Homework Equations N/A...

∫(dθ)/(a+bcosθ)^2 Homework Equations I'm trying to find the above integral (from 0-2pi) using Cauchy's Residue theorem. After closing the contour and re-writing the integrant, I know that I have singularity at (-a/b)+(√(a/b)^2-1)- (double pole or is it??). The Attempt at a Solution...

Homework Statement I have a transfer function: H(jw) = RCjwz / (1+RCjwp) and I'm being asked to find R, if C = 47nF and the desired pole frequency is at 3.3kHz. what I'm confused about is that the pole frequency is supposed to make the denominator of the transfer function 0, but...

So does a wire actually have a magnetic north and south pole? I know a coil of wire will form one but a straight wire will only attract another wire if the other wire's current is going in the opposite direction and repel if in the same direction. I have looked for images and they always just...

This is the barn pole paradox using a slightly curved pole and a silo instead of a perfectly straight pole and doors on a barn. Let's say we have a pole of proper length of 1 light-year that is traveling around a circle that has a curvature of 1 meter over 1 light-year of length. Let that pole...

The following diff. equation describes the functionality of a system with respect to time. However, it is not known how the system will behave when stimulated. Apply a forward Laplace transform to determine damping ratio and pole zeros. Plot a pole zero diagram and comment on stability. d2y/dt2...

Electricity and Magnetism (Polarity) Homework Statement Draw and indicate the current flow for the following situtions a) A north pole entering a coil wound counterclockwise b) A north pole exiting a coil wound counterclockwise Also is you could please explain coils, and...

Hi! I'm really excited about recent APoD picture, which shows Cassini's photo of a gigantic storm on Saturn's north pole. They also have an animation! I can't wait for a colour picture and videos. Meanwhile, since I still didn't state the purpose of this thread, what are the inner vortex...

Here's a vector tent problem with the solution. Can someone please explain it to me. https://docs.google.com/open?id=0B7WWo1BlPRXKSTU5WGRLZ2NaX2c

I just posted about the new parameters here: https://www.physicsforums.com/showthread.php?p=4152380#post4152380 Basically the new numbers look rather close to what Jorrie already put as the default in his calculator. zEQ looks familiar. Hubble rate 70 looks familiar :biggrin: Here's the...

Homework Statement A tetherball with a string length of 1.5m is hit in such a way that it completes a circle around the pole with the string at 30 degrees from the pole. Assuming it doesn’t lose a significant length during the trip around the pole and hence takes a perfectly circular orbit...

Form factors in QCD are given in following form "f(q^2)=f(0)/(1-q^2/m^2)". This expression has a pole at q=m. How do we plot these form factors vs center of mass energy and deal with the pole.

According to me Transfer function will be G(s)= (s2+2ζωn+ωn2)/((s+p1)(s+p2)) I assume from the given plot that ωn < p1 and ωn < p2 Then the bode plot will be as per me like following :From the Bode plot we can see for higher freq magnitude is amplified . So it will be High pass Filter. That's...

Assume there's a person standing at the pole of the earth. When the Earth rotates, he/she has no tangential velocity because the person is at the pole. Now if the person were to take a trip by plane and land at the equator, the person would now have a fairly large velocity because the...

Here's a question from a coworker: Based on the idea that the tips of fan blades move faster the base relative to the center of the fan, if you were to somehow put a very, very (impossibly) long pole through the spinning Earth, could the tips of the pole reach c or faster given that the pole...

Hi, This is my first post, and if this is the wrong area, I apologize. I was wondering if anyone knows of a software package that will design the pole faces for a quadrupol or hexapole electromagnetic beam focusing magnet given the beam parameters and electromagnetic magnetic field strength...

Homework Statement An old wooden telephone pole with a single cross member was blown off center during a recent storm. To temporarily stabilize the telephone pole, a repair crew has attached a cable from the end of the cross member to an eye-ring stake anchored in the ground. (Figure 3) If...

Hello, I was reading my textbook and watching MIT Opencourseware and noticed a discrepancy between the two. There was a string attached to a massless ring on a pole without friction, on the MIT website it said the ring will go twice the amplitude of the wave, but in the textbook it said it...

Hey all, I am doing a Schwarz-Christoffel transformation and I am trying to calculate the integral analytically using the residue theorem. My integral is the following: \int^\zeta _{\zeta_0} (z+1)\frac{1}{(z+2.9)^{{b_1}/\pi}{(z-0.5)^{{b_2}/\pi}}}dz This has two poles at -2.9 and 0.5. b_1 and...

http://www.bbc.co.uk/sport/0/olympics/19179092 Is this an example of the Feynman spaghetti problem?

Having a fair bit of trouble with this one. Based on the answer I had thought to apply the Sine Rule but adding points to describe the lengths of elevation seems wrong, but I'm stuck on how else to approach this. Can anyone help, please? Many thanks. Homework Statement Q. A vertical...

Homework Statement A man 6ft. tall is standing x ft. from a light pole 15 ft. high. Express the length of the man's shadow L as a function of x. Homework Equations Pre-Calc. NO TRIG The Attempt at a Solution I assumed that the man's shadow creates another like triangle within in the larger...

Find the gravitational attraction of a solid hemisphere of radius a anddensity1 on a unit point mass placed at its pole. My attempt: Obviously I figured that spherical coordinates would work nicely for this problem. I decided to invert the hemisphere thus placing the pole on the origin...

Sorry if i post this one in wrong thread, But can you help to solve this one? so i can review or study it by my own.. :D thanks!

I've been studying the residue theorem and I've been having some difficulty with classifying singularities. For example, let's use the function f(z) = \frac{1}{z sinz} I know it has two singularities, one at z=0 and the other at z=2kπ for k ={0,1,2,..}, I don't know what kind of singularities...

I'm having trouble understanding how a pole mounted transformer is wired. I am astounded at how little information is online about one of the most common devices on the grid. The typical single phase transformer has a single wire connection from one high voltage power line. To have a...

If a complex function has the form: f(z) = g(z)/(z-a)n then z=a is a pole of order n. I don't really understand all this fancy terminology. Isn't a pole just like when you for a real valued function g(x)/(x-a) don't want to divide by 0 and therefore the function is defined at x=a? If so what...

Firstly does log(z) have any singularity other than z=0? Secondly, z=0 is a pole of what order for log(z)? What is the Laurent series expansion for log(z) at z=0?

The sun has begun its 11 year magnetic polar reversal a year early, with the north jumping the gun on the south. http://www.sciencedaily.com/releases/2012/04/120421203959.htm "Right now, there's an imbalance between the north and the south poles," says Jonathan Cirtain, a space scientist at...

I am curious which math classes gave people the most trouble during their time in college. I am not looking for a "this class is harder than that class" kind of ruling as I know it differs from student to student and school to school. I am simply curious to see if there will be a pattern in the...

Hi, I was wondering about how to determine the residue of a pole that is written in the form: f(z) = \frac{1}{(1 + t^r)^{\frac{m}{r}}} Here: m \in \mathbb{N}\,\,\,\,\;\,\,\,\,r \in \mathbb{R} And if it's possible, r could be complex. Would the order of the pole be m? Implying that...

Homework Statement Give two reasons why the apparent position of the Earth's geomagnetic pole, as recorded by ancient rocks, may not correspond to its present position. The Attempt at a Solution Continental drift? So what is recorded by ancient rocks is not totally accurate because it...

Hi, I was hoping someone may be able to help me understand what Arfken is doing in sec 7.2 when he does the pole expansion of meromorphic functions (he says this proof is due to Mittag-Leffler). So he starts off with a function f(z) that is analytic except at some isolated poles. These poles...

Find the integral $$ \int_C\frac{dz}{z^2 - 3z + 5} = \int_C\frac{dz}{\left(z - \frac{3}{2}-i\frac{\sqrt{11}}{2}\right)\left(z-\frac{3}{2}+i\frac{\sqrt{11}}{2}\right)} $$ Where the path is a rectangle oriented clockwise from (0,0) to (0,4) to (10,4) to (10,0) to (0,0). So $z_1 =...

Prove that there is no function $f$ such that $f$ is analytic on the punctured unit disc $\mathbb{D} - \{0\}$, and $f'$ has a simple pole at 0. Let $f$ be analytic on the punctured disc $\mathbb{D} - \{0\}$. $$ f(z) = \frac{g(z)}{h(z)} $$ such that $h(z)\neq 0$. Then $$ f'(z) =...

Hello everybody, I have a (potentially strange) question. Let's say an electron enters a magnetic field; what happens with the north pole of the electron over time? At the end it will obviously be aligned with the magnetic field, but what happens before that time? For example, would the...

In South Pole, In which direction will the sun rise?

According to Wiki: "If a beta function is positive, the corresponding coupling increases with increasing energy. An example is quantum electrodynamics (QED), where one finds by using perturbation theory that the beta function is positive. In particular, at low energies, α ≈ 1/137, whereas at...

Homework Statement The flag pole is 10m tall. The base of the pole has rusted and the pole topples over. What is the time taken for the pole to hit the ground? s = distance = 10m u = initial velocity = 0 m/s v = final velocity = unknown a = g = acceleration due to gravity = 9.81 m/s2...

I have this problem where a pole is vertically balanced, and there are three wires attach on top of it. The wires are fasten to the ground. It looks like a three side pyramid. The question tells me that one of the cable has a tension of 6000 Newtons. How can I find the tension on the other two...