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...
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...
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...
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...
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...
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} =...
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...
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...
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?
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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?
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...
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...
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...
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...
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...
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...
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...
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...
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)...
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?
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...
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...
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...
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...