Spiral Definition and 182 Threads

Homework Statement A particle moves outward along a spiral. Its trajectory is given by r=Aθ, where A is a constant. A=1/π m/rad. θ increases in time according to θ=αt^2/2, where α is a constant. Show that the radial acceleration is zero when θ=1/√2 rad. At what angles do the radial and...

Hi everyone, I am trying to get an intuitive grasp of the Euler Relationship e^i(theta)=cos(theta)+i sin(theta) and also understand how to graph the exponential spiral, as demonstrated on this web page: http://www-math.mit.edu/daimp/ComplexExponential.html" Ok, first the neuron...

So far i have found two theorise of how they form, the SSPSF shock wave model ,and the Density wave model, or they may form by a combination of the two. As i am not sure how old these theories are, i wonder if there are any new insights on the subject?

Two identcal spiral galaxies A and B with equal but opposite momenta a and b are merged to form a resultant galaxy C with a net linear momentum c. Which is true? a) c>b b) 0<c<b c)c= abs(b)+abs(a) d) c=0

Prime "spiral"?.. Sorry i don't know the name of this "Phenomenon" i heard (due to Sierpinski perhaps?) that if you distributed the prime numbers into an square in some manner there was an spiral that..run over all primes or something similar...i think it was called "Sierpinski spiral" or...

Spiral Tracer?? Hello. Has anyone ever heard of a spiral tracer? and what characteristics they have?? any good link on the topic would also be appreciated thank you

Astronomers have made the most detailed map ever of our galaxy's overall shape, showing that its spiral arms extend much further than expected. Evan Levine, Leo Blitz and Carl Heiles of the University of California at Berkeley analysed the distribution of atomic hydrogen in the Milky Way at...

This topic could well be in a section related to biology, but more people visit the GD area. So... http://physicsweb.org/articles/news/10/3/8/1

Obivously, the direction of the rotation of a Spiral Galaxy depends on the vantage point from which you look at it. From Earth, do all Spiral Galaxies rotate in the same direction? Or, because the universe is so vast, the rotation direction is irrelevant and has morre to do with prior collisions?

how can this be explained?

from http://stardate.org/radio/program.php?f=detail&id=2005-12-08

Orbiting electrons have a constant acceleration towards the centre but why must it radiate photons as it accelerate? Thanks

What is cornu spiral?

Four ants are situated at each vertex of a unit square. Suddenly, each ant begins to chase its counterclockwise neighbor. All the ants travel at the same speed and eventually,they all meet at the centre of the square. What sort of spiral is traced out by each of the ants? :confused:

I thought this Slashdot story might be appropriate for here.

I hope this is the right section. But, can anyone here tell me how is it that we know the our galaxy is a spiral one, i don't doubt what I've read, but i need an explanation. I read something about density waves and how they power the rotation of our galaxy andor other galaxies. But how do we...

Hello, Can anyone please help me with this question? I need to get it done VERY soon. If someone could post a full solution I would be extremely grateful. It's probably very easy for someone who understands parametric equations and polar coordinates and such. I don't at the moment! I...

Let we have a piece of wire, copper, for example. Let we have the generator of alternating current with changing frequency. We connect the ends of a wire to clips of generator of an alternating current and then turn it “ON”. Resistance of a piece of wire does not depend on frequency of a...

What are three distinguishing characteristics that can differ among spiral galaxies?

I am having trouble getting started with this problem.. I guess I'll explain it first. Find one possible matrix A for which the solution to Y'=AY with initial condition Y(0)=(6,13,9) has the following property. As time progresses, the solution Y(t) spirals toward the plane 2x+3y+4z=0 where...

Howdy I'm having a ton of trouble with this question Basically I have a spiral coil running around the z-axis with radius 'a' height '2b' and pitch 'c'. The point (x,y,z) = (a,0,0) is on the spiral and n = 2b/c (that's the number of turns on the spiral). There's a steady current running...

given the parametric eqns for a spiral x=kt cos t y=kt sin t where k is a constant give a function of 't' that calculates the length of the spiral.

how can I calculate the "diameter" of a spiral ? someone told me i need to use Differential or Integral Equations to solve this, but I'm not sure how. If there is a spiral that it's radius increases by 1 cm for every radian until the radius reaches the size R . how can I calculate the...

There is a spiral but it is just on the yz plane (no length to it) I need to integrate it. And I'm at a location x on the axis if it matters. Thanks

Perhaps this has already been brought up, but is an electromagnetic wave 2-dimensional or 3-dimensional? The current "up-and-down" concept does not have me convinced. If you look at a standard spring, you can see that it is a spiral/helix. You can also see that the side of the spring...

The following site shows that when a sail is orientated so that it faces away from the sun, the net force is pushing outwards from the sun and is also opposing the orbit. http://solarsail.jpl.nasa.gov/introduction/how-sails-work.html It makes sense that the craft should slow down, but why...

a spiral given by r(t) = (e^-t cos t, e^-t sin t) , t is greater than or equal to 0, how would i find the length of the spiral? thanks anyone!

In the nucleus of a spiral galaxy the most stars are old population II stars, and there is no star formation (which occurs in the spiral arms). Why? Thanks.

During orbital’s filling with electrons, power areas form inside atom - with superfluous quantity of electrons and insufficient quantity. It causes overjumpings of electrons. My theory about such overjumpings see on www.genevo.org. I nead your comments

Hello all, I'm working on a diagramming program that uses the golden spiral to make templates for something I'm working on. I'm wondering if someone can tell me how to get the equation of the tangent line at point (x,y) on the spiral. My program graphs the spiral parametrically and I use these...

http://www.Givnology.com/wholy.htm Sure, that's simple. Focus on bringing in lunar nose, then solar nose, and be the DNA microcosm of the universe, surrounded by spiraling energy bands (not snakes!), and finally consumated in the crown where they're "making out." Well at least there is a...

The "Golden Spiral" - Calculating intersections with circles. Hello all, I am working on a program that graphs the Golden Spiral and then lays a set of circles on top of it. I was curious to know if there is a formula I can use to figure out the x, y coordinates where a circle of a given radius...