Pole Definition and 372 Threads

  1. V

    Sunrise Direction in the South Pole

    In South Pole, In which direction will the sun rise?
  2. W

    What is the Landau pole and how does it relate to the coupling constant in QED?

    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...
  3. C

    What is the time taken for a flag pole to fall over and hit the ground?

    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...
  4. V

    Question on vertical pole and equilibrium

    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...
  5. MacLaddy

    Pole in a corner - Trig word problem

    Homework Statement A pole of length L is carried horizontally around a corner where a 3-ft wide hallway meets a 4-ft wide hallway. For 0 < \theta < \frac{\pi}{2}, find the relationship between L and \theta at the moment when the pole simultaneously touches both walls and the corner P...
  6. M

    Finding the residue of a pole of order 2 (complex analysis)

    The problem Find Res(f,z1) With: f(z)=\frac{z}{(z^2+2aiz-1)^2} The attempt at a solution The singularities are at A=i(-a+\sqrt{a^2-1}) and at B=i(-a-\sqrt{a^2-1}) With the normal equation (take limit z->A of \frac{d}{dz}((z-A)^2 f(z)) for finding the residue of a pole of order 2, my attempt...
  7. Greg Bernhardt

    Is There Summer Ice at the North Pole?

    I'm trying to find information on whether there has been summer ice at the North Pole the last few years. I've found a couple old articles that indicate scientists predicted no summer ice. Did this in fact happen and is it predicted again for this coming summer? Does that mean the North Pole...
  8. H

    A 59 kg pole vaulter falls from rest from a height of 4.7 m onto a

    a 59 kg pole vaulter falls from rest from a height of 4.7 m onto a foam rubber pad. the pole vaulter comes to rest 0.34 seconds after landing on the pad. calculate the athlete's velocity just before reaching the pad. calculate the constant force exerted on the pole vaulter due to the collision...
  9. M

    Martian Pole Star: Same as Earth's?

    martian pole stars same as Earth pole stars ?
  10. L

    Weight at the North Pole vs. Equator Problem

    1. Suppose Earth is a perfect sphere of radius 6,370km. If a person weighs exactly 600N at the north pole, how much will the person weigh at the equator? Givens: r = 6,370km = 6,370,000m Weight at north pole = mg = 600N Homework Equations ω_{av} = θ/t ƩF_{net} = ma a_{c} =...
  11. M

    S^2 union a line connecting the north and south pole

    I have been trying to determine the fundamental group of S^2 union a line connecting the north and south pole by using the Seifert Van Kampen Theorem. But every time I try and pick my two subsets U and V they are either not open or not arcwise connected or their intersection isn't particularly...
  12. L

    Special relativity assignment - pole moving in two dimensions

    Hi! I'm a bit stuck with this special relativity assignment, here's is the problem: So the problem here is that not only does the hole shrink in S', as stated in the problem description, the pole should also be wider by a factor of 3 in this frame. So we have an 18 ft wide pole that has to...
  13. N

    South Pole colder than the north pole. why ?

    South Pole colder than the north pole. why ? Hello .. I have a question .. Why the South Pole colder than the north pole ? (for the earth).
  14. K

    Soft landiing an asteroid at the south pole

    can a small nickel/iron asteroid brought near Earth (matching its solar orbital velocity) and soft landed at the south pole where Earth's rotation is not an issue?
  15. C

    Tension problem - bead sliding on a string attached to a pole

    Homework Statement A 100 g bead is free to slide along an 80 cm long piece of string ABC. The ends of the string are attached to a vertical pole at A and C, which are 40 cm apart. When the pole is rotated about its axis, AB becomes horizontal. Homework Equations F = ma...
  16. P

    Newton's 3rd Law - Firefighter slides down a pole

    Homework Statement A firefighter who weighs 712 N slides down a vertical pole with an acceleration 3 m/s2, directed downward. What are the (a) magnitude and (b) direction (up or down) of the vertical force on the firefighter from the pole and the (c) magnitude and (d) direction (up or down) of...
  17. M

    Google earth image of the South pole?

    Hi , I wonder why the image of the south pole in google Earth is blurred ?
  18. P

    How Does Norman Nise Explain Forced and Natural Response in Control Theory?

    I am reading a book on Control Theory by Norman Nise. I don't get his description of forced and natural response based on poles and zeroes. I have posted a screenshot of the page http://www.flickr.com/photos/66943862@N06/6134272368/sizes/l/in/photostream/" . I understand upto Eq 4.2...
  19. D

    Bending Moment on Pole due to Wind

    Hello Friends. I have a question for the following scenario: There are two wooden poles, both set into the ground so that they are sticking straight up. The height of Pole One is H1 feet. The height of the Pole 2 is H2 feet. Supported in between these two poles is a wire. The ends of the...
  20. B

    Steel Pole Strength: Calculating Thickness & Weight Limits

    Hi, I am a newby to all of this, can't find any good answers on the internet, hope someone with experience can help! If I have a solid steel pole with a length of 50 cm, hang this from a roof, and want to hang a 7 kg object from this pole, how thick does the pole have to be? If I reduce...
  21. S

    Dropping a mass directly over the north pole

    Hi all, I'd like to understand what would happen to a mass which is dropped at the north/south pole. Let's say you raised a mass to a certain height over a certain point, which we will call A. Point A is at the center of the north pole. The height at which the mass is raised is such that...
  22. S

    Electro magnetic craft levitation at earths magnetic pole possible?

    the reason for this idea is to replace most rocket fuel needed for soft re-entry with other type of energy into Earth's atmosphere (NOT to move around, just slow down) lets assume you have a HUGE energy supply and a craft with capability to generating an electromagnetic field (direction of...
  23. B

    Understanding the Simplicity of Pole at z=+i for h(z)

    Homework Statement Why is the pole at z=+i simple for the function 1/(1+z^{2})? Homework Equations The function can be written as: h(z)=1/(1+z^{2})=1/[(z-i)(z+i)] It can be expanded as a Laurent series: h(z)=\sum^{\infty}_{-\infty}a_{n}(z-z_{0})^{n} The function is defined as...
  24. T

    2 pole 4 pole 8 pole motors

    Hi All, Can anyone care to explain what are 2 pole 4 pole 6 pole 8 pole motors? What are the Asian Countries specfically use for them?
  25. Femme_physics

    Solving Tensions and Reaction Forces of Pole AB

    Homework Statement http://img101.imageshack.us/img101/9546/3dstats.jpg Pole AB is supported at point A by a pin joint, and held at point B by two wires, BC and BD, as described in the drawing. At point B acts on the pole force F which equals 500 [N]. The force F acts on a horizontal...
  26. D

    A virtual pole vaulter in the relativistic barn

    I have sent approximately the following to a relativity prof at my university. It's summer, so I don't know if he'll read it, or be interested. So here it is for discussion. Hello, I wonder if you could tell me if the following experiment would have merit. To measure actual...
  27. K

    Barber's pole - appear faster than light?

    Hi, so imagine this: You have (for this theoretical situation) an entirely massless barber's pole. When it spins, the speed of the of the circumference of the pole is less than the speed the line appears to travel up (or down) the side of the barber's pole. If you were to spin the pole, could...
  28. D

    Zero & Pole Plots: Filters, Frequency Response & Impulse Inputs

    Hi I am after any information regarding zero pole plots, specifically with reference to filters. I understand the process of getting the transfer function and plotting it. But once its been plotted how do you go about translating that into a frequency response. I am also wondering about...
  29. F

    Does a North Pole Magnet Attract or Repel Metal?

    My question is: does a north pole attract or repel a piece of metal ? My attempted answer is: I think that the north pole alone would not attract a piece of metal. Instead it would require the north pole in conjunction with the south pole to attract a piece of metal. Can someone please confirm...
  30. S

    How Do You Tell Time at the North Pole?

    Hey guys, can anyone please tell me how to calculate time on the north pole? will there be any local time on north pole?
  31. K

    Spinning at the North Pole: Equator to Arctic Teleportation

    If You are suddenly teleported from the equator to the north pole. How fast and which way will you be spinning relative to your surroundings?
  32. T

    What are the consequences of pole reversals on Earth

    I was told today by my physics professor that the Earth undergoes magnetic pole reversals, some of the evidence being molten rocks with magnetic properties on Earth orientating themselves towards a different north pole which points towards the north pole being different in the past. He said that...
  33. F

    Could Morse Code Be Instantaneous on a Million Light-Year Pole?

    Suppose a pole could be constructed that was one million light years long and was completely incompressible. If someone on one end tapped out Morse code on their end, would a person on the other end be able to receive the message instantaneously?
  34. Z

    Time period of oscillation of a pole floating

    Time period of oscillation of a pole floating... Homework Statement A pole is floating in a liquid with 80cm of its length immersed. It is pushed down a certain distance and released. What is its time period of vertical oscillation? The Attempt at a Solution I think the information...
  35. B

    Calculating Apparent Weight Difference Between Equator and South Pole

    Hello all, just a few problems that I've worked through, just clarifying if I'm on the right track. Thank you in advance. 1.) The radius of the Earth is 6378.1 km and completes one revolution per day. Calculate the difference in apparent weight between a person of 65kg mass, standing on the...
  36. H

    Magnet with single pole creation

    Hi, I am proposing a simple way to create a magnet with single pole. Not being a physics/science graduate, this came out of interest of thinking only. Lets consider a sphere, which is hollow inside and has a thickness to it at the surface only. If i cut a certain segment and make it out of...
  37. B

    Caunchy's Integral Formula w/ trigonometric pole

    Homework Statement Solve the contour integral \int_{\gamma}\frac{2+z}{1-cos\left(z\right)}dz along a counter-clockwise circle of radius 1 centered at z=6 Homework Equations Cauchy's integral formula f\left(z\right)=\frac{1}{i*2\pi}\int_{\gamma}\frac{f\left(w\right)}{w-z}dw The...
  38. S

    What is the difference between simple fixed pole and simple movable

    What is the difference between simple fixed pole and simple movable pole? Differential eqs. z(dw/dz)+w=0, corresponding solution w(z)=c/z, and (dw/dz)+w^2=0, corresponding solution w(z)=1/(z-c) where c being the integration constant. In the solution given above Ist equation has a simple fixed...
  39. P

    Second order pole positions and rise time

    Dear All I'm stuck on something that seems to be contradictory. I was under the impression that the further the 2 closed loop poles are in a 2nd order system to the left of the root locus, the higher the damping. Surely high damping means longer rise time? But other sources say that the...
  40. R

    What is the Hall Sensor IC and how does it detect North and South poles?

    Hello everyone, I've been looking for an IC that can detect a North pole and/or a South pole. I know that there are pens or wands that can do this but what is it in the wand that detects either pole. I'm working on a spining magnet flywheel essembly that has an array of north oriented magnets...
  41. S

    Linear Speed at South Pole Antarctica

    What would be the linear speed of body in Antartica standing on a south pole.
  42. V

    Engineering Electrical Machines and Power Electronics - 3 phase, 6 pole induction motor

    Homework Statement A three phase, 6-pole, \Delta connected induction motor is rated 208V, 60Hz. It has R_R\,=\,5.2\,\Omega, R_S\,=\,2.2\,\Omega, X_m\,=\,220\,\Omega, X_{lr}\,=\,7.5\,\Omega, X_{ls}\,=\,2.3\,\Omega. Calculate the starting torque and both phase and line currents when the motor...
  43. C

    Calculating the Velocity of a Fireman Sliding Down a Pole

    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) <(or equal to) (d) above the ground and descended with negligible air resistance. In terms of (g), (h), and (d)...
  44. A

    Double Pole Switches: Do They Have an Off Position?

    do all double pole switches hav an 'off' position? what is the operation of a transfer switch? what is the most common application of a three-way switch? what is the most common application of a 4-way switch?
  45. M

    Why positive or negtive pole of battery can not attract small objects ?

    why positive or negtive polar of battery can not attract small objects ?
  46. I

    Climbing a Steel Pole in <8 Secs - Ideas?

    Hey guys, with little to none FORMAL physics application experience myself, but quite a bit from the other members in my club. I was wondering what you guys think the fastest methods to climbing a pole would be. Some limitations we have are : one 12vDC battery, only 2 motors (about 150 rpm), and...
  47. P

    Finding the Forces on a 7.5m Aluminum Pole

    Homework Statement A 7.5 m long uniform aluminum pole with a mass of 12.0 kg supports a 21.5 kg traffic light. The aluminum pole is attached to a vertical pole by a pivot near the base. A massless horizontal rope supports the aluminum pole and is connected to the vertical pole 3.80 m above...
  48. D

    Can We Colonize the North Pole?

    Would it be possible to colonize the North Pole? I was just wondering.
  49. P

    Step Response of System with Pole in s = 0 at Infinity

    Homework Statement A contininous time system has when laplace transformed, a pole in s = 0. What is de stepresponse for the system when t goes to infinity Homework Equations H(s) is infinity in 0 (H(s) is unit response laplace transformed) s(t) = h(t) * u(t) (the stepresponse is the...
  50. G

    How Can You Solve an Integral with a 2nd Order Pole on the Real Axis?

    I'm working on a complex analysis problem from Arfken. Integrate[ (cos(b*x)-cos(a*x))/(x^2), {x, -Infinity, Infinity}] and show that it is equal to Pi*(a-b) Attempt: I first look at a related problem (or one that I think is related). => f(x) = sin(x)/x => f(z) = sin(z)/z...
Back
Top