Pole Definition and 368 Threads

Hello, In the same frame of reference and using the same coordinate system , the magnitude of mechanical torque depends on the position of the center of rotation (pole): the lever arm distance varies depending on where the pole is. For static equilibrium situations, the net torque is zero so...

If someone was sliding down a vertical pole (like a firefighter) would only friction need to be considered to find out how fast the person is "falling" or is there also normal force from where the person is touching the pole, and would that affect the person's speed down? (I am ignoring air...

I'm working on a public area audio system where we need to install our horn speakers on big height as per their installation requirements. We designed a metal pole as described: Pole consists of two poles: 1) a 7.5 meters height, 10" diameter, 6mm thickness. 1.5 meters are to be buried...

Hello, I read that Golgi Apparatus when examined below the electronic microscope, appears a network of fibrils either apical or perinuclear. And it is apical when the Golgi apparatus is between the secretory pole and the nucleus in secretory cells. I don't know what exactly is the "secretory...

Homework Statement Homework EquationsThe Attempt at a Solution First and foremost I am not sure about how the particle moves around the pole .Can it keep moving in horizontal circle .Or do we have to assume this . Is it something like a conical pendulum ? I don't have much ideas to solve...

Would like to know how to determine if 2 additional pair of rotor pole shoes can be added (re-designed) to rotor for existing 72 slot alternator stator. Present claw pole rotor has a total of 12 and I would like to have a total of 16. Any assistance would be appreciated. Thank you.alternator...

Homework Statement A pole BC is supported by the cable AB as is shown in the figure. If the magnitude of the force applied on the point B is 70 lb, and the moment of this force about the x-axis is -763 lb ft, determine the pole lenght. I'LL ATTACH AN IMAGE SO YOU CAN SEE IT. Homework Equations...

I'm trying to understand the difference between these two when it comes to measuring the amount of time they take. As of right now, my current understanding is that pole relaxation is based on the amount of time that it takes for polarization of the charges to go back to its relaxed state. For...

Homework Statement i know problems of this kind have been posted a lot but i have a few of my own questions please take a look at them thanks i am having several conceptual errors in rotational dynamics one of them is : since the rod is massless must there be net zero force and torque...

Hi I am trying to understand the figure 2 I have attached to this post. From text: Ok, I get that the air-gap flux density varies in a sinusoidal manner, because the air gap length is not constant i.e. non-constant reluctance and hence non-constant magnetic flux density. What I do not...

Lenz's law shows that dropping a magnet through an aluminum pole will cause an induced current that slows down its fall drastically. I found a website that talks about this a little: https://www.lhup.edu/~dsimanek/TTT-slowfall/slowfall.htm It has the following question: I don't see any...

So the circle minus the pole is homeomorphic to the number line. Does that mean that the pole itself represents a number that doesn't exist on the real line? After all, the pole certainly exists and yet is the only point that isn't mapped.

From time to time I like to chat with flat Earthers and help them clear up their confusion. Today I came upon a question I couldn't answer, and since it is summer, I couldn't ask a professor. Would two people, on two separate planets, holding one pole, feel a push from the other...

Homework Statement A fireman of mass m slides a distance d down a pole. He starts from rest. He moves as fast at the bottom as if he had stepped off a platform a distance h≤d above the ground and descended with negligible air resistance.What average friction force did the fireman exert on the...

Hi all, I tried to post in this post https://www.physicsforums.com/threads/salient-and-non-salient-pole-synchronous-generator.878198/ but I now realize that creating a new thread might have been better.So... Salient rotors are not used in high rotational speed applications, and we must use...

Homework Statement An olympic athlete with ~30 kg mass is participating in pole vaulting. The athlete runs and, at the moment of the jump, he has a velocity of ~10 m/s. Calculate the maximum height he can reach. To solve these kinds of problems, we can just convert all the kinetic energy the...

I'm trying to figure out what type of motor I need to use that has the ability to lift a 7'-9' pole that has about 5-8 pound weight attached to it at the end. The max angle that the poll will be is 180 degrees and the motor will need to lift it to 90 degrees. As for the weight its not a free...

In the B level thread:..."how to change electron and proton charge"...it was claimed that "the closer you get to an electron the bigger the charge". This struck me as odd because I though that electron charge was a fundamental constant and so I asked for clarification. This was given but extra...

Homework Statement Determine the order of the poles for the given function. f(z)=\frac{1}{1+e^z} Homework EquationsThe Attempt at a Solution I know if you set the denominator equal to zero you get z=ln(-1) But if you expand the function as a geometric series , 1-e^{z}+e^{2z}... I...

I am trying to numerically integrate the following complicated expression: $$\frac{-2\exp{\frac{-4m(u^2+v^2+vw+w^2+u(v+w))}{\hbar^2\beta}-\frac{\hbar\beta(16\epsilon^2-8m\epsilon(-uv+uw+vw+w^2-4(u+w)\xi...

Not sure if this is the best place to ask this question but forums on this seem to be limited, can anybody explain how one would discover if a steel pole lighting structure is being effected by harmonic resonance? I do not know what tools and methods would be used, if anyone can provide some...

Homework Statement A uniform metal pole of height ##30.0m## and a mass ##100kg## is initially standing upright but then falls over one side without its lower end sliding or losing contact with the ground.What is the linear speed of the pole's upper end just before impact ? Homework...

Homework Statement May I ask you something about a task from the last years test at faculty of mathematics and physics, University of Ljubljana, Slovenia ... There is a disk at the end of a pole. We cause some F dt tangentally on the disk, which causes the change of momentum. I need to...

Hi. Since there haven't been observed magnetic monopoles so far, what exactly do we mean when we talk about the north/south pole of a magnet? Is it something like "north is where the field lines exit a solid body" and "south is where they enter" or is there a more rigorous definition?

Homework Statement A horizontal pole is made of 8 pieces, 1 meter apart each. Forces that do not act at the ends are shown in the picture. The pole does not rotate, and weighs 20N. a. What is the sum of forces applied on the pole? b. Where is it applied? c. What are the forces at the ends...

Homework Statement In the beginning a point mass is rotating in a circle of radius L. The spring is providing the centripetal force (\vec{F}=-k\vec{r}) and the mass rotates with constant speed. At some point in time, a stick of radius a (a<<L)lands near the center of the circle in such a way...

Homework Statement Homework Equations p=nsf δ=mϒ Kd=[sin(δ/2)]/msin(γ/2) Kp=cosε/2 e.m.f=4.44TφfKdKp The Attempt at a Solution i do not know why pole pair =2 and it is short 2 pitch. how can i find pole pair and short pitch from its original developed diagram? i know that Phase spread=60(we...

If a general conic is ax^2+2hxy+by^2+2gx+2fy+c=0 I am told that, if P(p, q) is a point on this conic, then the polar of P(p, q) to this conic is apx+h(py+qx)+bgy+g(p+x)+f(q+y)+c=0 How is this derived?

The pole masses of the heavy quarks (c, b and t) are relatively well defined in QCD (i.e. the solution of m²(p²) = p² extrapolated using the beta function and the available data from other values of µ usually obtained based upon model dependent decompositions of hadron masses that include these...

Hi, I was wondering if some kind soul could explain to me why salient pole machines are preffered in hydropower? From what I've read salient pole machines are preffered for applications with "low" rpm, while non-salient poles are used for applications that runs at higher rpm. O What is the...

Ok, I've spent lots of hours browsing the web and the library and still this question is burning. How can i calculate, whether it be experimentally or theoretically, the " pole strength" of a magnet. (I have read about the experiment where you divide the work it takes to turn a magnet around a...

Homework Statement How would I calculate the residue of the function ##\frac{1}{(x^4+1)^2}## Homework EquationsThe Attempt at a Solution So I have found that the poles are at ##z=e^{\frac{i \pi}{4}}## ##z=e^{\frac{3i \pi}{4}}## ##z=e^{\frac{5i \pi}{4}}## ##z=e^{\frac{7i \pi}{4}}## I tried...

when a magnet attracts the north end of a compass, what does that mean?

1. Homework Statement The violet sleeve has mass M and is free to move horizontally without friction. The green rod has mass 2M and length L and can rotate around a pivot on the sleeve without friction. At t=0, the rod is in vertical position and is rotating with angular velocity w. What are...

Homework Statement Hi everybody! I'm stuck at a problem I was given in my special relativity theory class, can anybody help? A golfer is on the North Pole, on a flat surface perpendicular to the Earth axis and without friction. He places himself at distance L from the pole and hits the ball...

Homework Statement A pole-vaulter holds a 5.0 m pole. A barn has doors at both ends, 3.0 m apart. The pole-vaulter on the outside of the barn begins running toward one of the open doors, holding the pole level in the direction he is running. When passing through the barn, the pole just fits...

I came across this problem: Explain how you would determine which was the north pole of a bar magnet, without using any other magnet. I was thinking of using a solenoid, and dropping the magnet in. Then you can determine whether it was a north or south pole by whether the current flows...

Homework Statement A 80.5 kg firefighter slides down a pole while a constant frictional force of 300 N retards her motion. A horizontal 20.0 kg platform is supported by a spring at the bottom of the pole to cushion the fall. The firefighter starts from rest 3.25 m above the platform, and the...

what would happen if north pole of Earth becomes south pole and south becomes north ? What would be the chenges on Earth's climate or any other changes ??

Hello, all. I've just been working on Kleppner to touch up on my knowledge of mechanics and general problem solving skills and I'm running into a bit of trouble on this leaning pole one in chapter 2. 1. Homework Statement A pole of negligible mass leans against a wall, at angle θ with the...

From the perspective of someone at or near the exact north pole (where, for all practical purposes, they are not rotating), ignoring the gradual change of the stars as the Earth orbits the sun, would the stars appear to move at all in the night sky? Or would they be stationary because the...

Given a Yukawa coupling as a function of scale and a vev, how can I compute the corresponding pole mas? Understandably most paper explain how from a measured pole mass one can compute the running mass, for example, Eq. 19 here. However I want to compute the pole mass from the running mass. In...

Hello guys please help me on this... The next hurdle in my understanding of frequency compensation comes as following… As the text says… My problem is that as we move from point 1 to 2, the frequency increases so the phase shift should also increase..(as phase shift depends on frequency)…...

Homework Statement A 55.0 kg pole vaulter running at 9.0 m/s vaults over the bar. Assuming that the vaulter's horizontal component of velocity over the bar is 1.0 m/s and disregarding air resistance, how high was the jump? Homework Equations KE = 0.5*m(vavg)^2 The Attempt at a Solution KE =...

Homework Statement Homework Equations ΣF=ma The Attempt at a Solution I drew a free body diagram for a), but am unsure where to go from here. Do I have enough information to rearrange the equations above and solve for FN?

How to become a better pole vaulter, what are the physics of it?

The pole method of magnetostatics is presented in many E&M textbooks, particularly the older ones, to do computations in magnetostatics and even to try to explain permanent magnets. An equation that arises in the pole method is B=H+4*pi*M (c.g.s. units), where H consists of contributions...

Homework Statement A 0.5 kg mass is attached to a string that is 20 cm tall and anchored to a pole. There is an angle between the string and the pole. 1) What is the force of gravity on the mass in terms of the angle? 2) If the mass is pulled slightly to an angle of 5 degrees and if sin(theta)...

Hi, I have a question on the force necessary to bend a scaffold pole. I have a barn made of curved scaffold poles approximately 20 ft high at the apex and 30 ft wide at the base, having a hemispherical cross section. These ribs are spaced approximately 7ft apart. Along the sides of the...

why does the normal on a mass have different values at pole and equator