Universal Definition and 488 Threads

Okay to preface my question, we know the universe is expanding. We know that this is not uniform otherwise the distance between the Earth and Alpha Centauri would be increasing at the same rate as the distance between The Milky Way and M87, for example. I'm over-generalizing here for the sake of...

Homework Statement A space vehicle of mass 555kg, experiences a gravitational pull from Earth of 255N. The mass of Earth is 5.98x10 (to the power of 24) kg.How far is the vehicle a) from the center of the Earth, and b) above the surface of the Earth? Homework Equations FG = GM1M2/d squaredThe...

Homework Statement Mars has a diameter of .54 times that of Earth and a mass of .11 times that of Earth. Suppose a rover was launched on Earth with the mass of 525 kg. Remember that g is -9.80 m/s/s A) How much does the rover weigh on Earth? B) How much does it weigh on Mars?Homework Equations...

Universal mass <<<< than a proton? Of all the models and theories that are being tossed about as fact, the one that I have the most trouble with is that: prior to the Big Bang, ALL mass...the Dark Energy, Dark Matter, and the mere 5% that comprises all the visible structures...stars...

Space time Geometry and GR, taken from lecture notes http://www.mth.kcl.ac.uk/courses/cm334.html http://www.mth.kcl.ac.uk/courses/cm334/Lectures0910.pdf from pages 3 and 4 Newton's universal law of gravity is getting modified. it says using the result, from where this result...

I figure the answer is somewhere in the sticky FAQ above but I’m having trouble finding it. I’m hoping y’all can help. I understand the Michelson–Morley experiment shows that the speed of light is the same in all directions and that that is a postulate in SR. But just like every other...

So I calculate the momentum of a body moving with a constant speed along a circular path with mass m, tangential velocity v and radius r. Its angular momentum is mvr.kk. Good. Now what if I calculate the angular momentum from a point on the path of the circle. A simple calculation shows that the...

hello, I am a high school student from Alabama, and I'm in a college level physics class. We have just finished fluids and thermodynamics, but my physics professor claimed something that has me a little irked. according to my physics professor and the laws of thermodynamics, nothing can...

Newton's universal law of gravitation: F=-G \frac{m_1 m_2}{r^2} I'd like to set up the problem so the particle begins at t=0 at radius r=r0 and radial velocity vr=v0. And there is only a component of velocity, in the radial direction. (The particle is going straight toward the...

Homework Statement N refers to the set of all natural numbers. Part 2: From the previous problem, we have σn : N → N for all n ε N. Show that for any n ε N, σ(n+1)(N) is a subset of σn(N), where we have used n + 1 for σ(n) as we defined in class. 2. The attempt at a solution For Part 2, I...

Question on the universal "correctness" of mathematics I began thinking of this question long ago, but only now, that I am reading A History of Mathematics, 2nd edition, have I decided to ask for the perspectives and thoughts of others. I am slightly reluctant to ask this question, for it may...

Homework Statement In a book "How to prove it" by velleman, universal quantifier is defined as follows; To say that P(x) is true for every value of x in the universe of discourse U, we will write \forallxP(x). This is read "For all x, P(x)". The symbol \forall is called the universal...

I have a treadmill that has a display monitor that uses either 4 D cell batteries or an optional adaptor. The back of the monitor states it uses a 6v 1.66-2.0a/max input. I purchases a universal power adaptor that has a fixed amp rating of 3 (6v obviously is an option). The question is: what...

The plane wave decomposition is mathematically universal? 1. My questions is: Can "expi[wt-(w/c)*r]/r with r=sqrt(x**2+y**2+z**2), the frequency w is given, monochromatic wave" be represented as a sum of uniform plane waves? Note: r=0 is a singularity. This is actually the potential...

Can anyone tell me that why we take r square instead of r?

Hello all. For some reason or another, I've been thinking about the following space: Take two copies of the square. Identify their edges as you would usually to form a torus, but identify them also to the corresponding edges of the counterpart sqaure (so we have two tori, joined in some...

It is my understanding that, except for a couple of local galaxies, everything in the universe is moving away from us as well as from each other (relationships between inhabitants of local galactic groups excepted). If my information is acurate, how is it that a large collection of randomly...

I was wondering if somebody could please explain the gravitational constant to me and also if they could give me the correct equation for it and explain the equation, because I have been receiving many odd variations of the gravitational constant and I would really like a good clear explanation...

The following thought/problem recently hit me: What the hell happens to photon energy lost due to the cosmological redshift?

Homework Statement what is the magnitude of Gravitational force for the following picture(s) (attached to forum) Homework Equations Fg = G M*M/D^2 The Attempt at a Solution I tried to do some of them I know the equation for the second one is fG = 2G M*M/D^2 and for the third one...

Gauss, Poincare, Euler, Hilbert, Riemman, Cantor, Godel all stand out as universal mathematicians. I define universal as either contributing to a vast number of fields of mathematics in quite distinct areas or someone who has changed the entire face of mathematics as it stands. That list is by...

There have been many posting (questions and answers) on universal rotation and there is a fine posting with references on the FAQ. Thanks to everyone for these. I don't pretend to understand the detail (especially of the maths), but I do understand most of the principles. However, there is one...

Ok so apparently the universal cover of the figure-8 can be represented by the cayley graph of the free group on two generators, discussed in Hatcher and here http://en.wikipedia.org/wiki/Rose_%28topology%29" i can see why this is a universal cover of the figure-8. but I'm having trouble...

I would like to have job tasks that are as interdisciplinary as possible. I'm trying to avoid boring routine work; regularly growing my skills and knowledge. Could aerospace and chemical engineering accomplish this goal? Also, is it common to work as an interdisciplinary engineer after you pass...

I have a question sort of related the size of the observable universe. I know that we are limited by the speed of light in how far we can see, but what I am wondering is... In the early universe when the first light could finally break free and travel in straight lines did it travel in...

http://www.newscientist.com/article/mg21028174.900-universes-highest-electric-current-found.html A COSMIC jet 2 billion light years away is carrying the highest electric current ever seen: 10^18 amps, equivalent to a trillion bolts of lightning. Philipp Kronberg of the University of Toronto...

Which are the Fundamental Universal Costants? With "Fundamental" i mean the ones that are not obtainable from others: for example, the light speed c is not fundamental, because is 1/sqrt(epsilon0 mu0)...

High guys, I've always had problems with this law at the way it was explained.But now I've seen lewin explaining that way that bothers me: In terms of sensations.At 1:50 http://youtu.be/M_8w-dD4RBE What I think is that we "feel" the pull only because we are made of multiple particles...

As the title says, I am confused - very confused. I know that the 2nd law of thermo means that the universe is increasingly disordered on a universal scale, even though there has been an apparent increase in order since the "Big Bang." Does that mean entropy isn't exactly synonymous with a...

A universal Turing machine is up to a log factor slower than the TM it's trying to simulate. What is the slowdown (depth increase, if any) of a universal circuit? Thanks in advance for the help!

steel floor beams span 7.0m and are at 4.2m spacing. the beams are fully laterally restrained by precast concrete floor slabs, 180mm thick, which they support. the floor has to support a speciified imposed load of 5.0 kNm-2. determine a suitable grade S275 steel universal beam section...

I found an article on arxiv which basically says that Newton's third law is not verified in certain situations...can anyone please explain more about this in layman terms?? Here's the link:- http://arxiv.org/abs/1104.5011v1

Hello, i am so confused Newton's universal gravitation states FG= Gm1m2/r squared and in this case FG stands for the force of gravitational attraction between any 2 objects, but why is Fg (gravitational field strength) equaled to fg=Gm/r squared? why are FG and Fg used interchangeably? i do not...

Hi, I'm taking an intro logic class and though I'm comfortable with most propositional logic, predicate logic is confusing me. I joined the forum to ask this particular question that I've been stuck on for a while. Any help would be appreciated - I'm having trouble finding information on the web...

1) Graph Fg vs. r Fg on y-axis, r on x-axis (from 1re to 6re) re (radius of the Earth) 2) If a cannon ball is fired from the top of Everest parallel to the Earth's surface fast enough (ignoring air resistance and assuming that it doesn't bump into anything), it will "orbit" the Earth and...

Does it apply to planets other than Earth? I'm just learning (cramming) this stuff; sorry if it's a dumb question.

Homework Statement Answers: 56. 6.16 x 10^17 N, 57. 894 N Homework Equations Fg = G*m1*m2/r^2 g = G*M/r^2 The Attempt at a Solution 56. Since the closest planet to Z is Y I figured the gravitational force could be calculated by just finding the gravitational force between Z and Y...

Firstly, Hi everyone :) Secondly, please forgive my virtualy non existent knowledge of any theories that this relates to. I'm not a Dr,MD, or even a graduate. I'm not even studying anything anywhere. I have a few 'problems' (chronic anxiety, depression, yada yada yada) not looking for sympathy...

I was looking at the gravitation constant and I didnt understand the parts of it with kg, and seconds. Could someone please explain in detail how to use this constant and give an example of some calculations? Thanks

Can i use a universal motor for pumping water? its speed may be around 6000 rpm & except gears what would be useful for coupling the pump?

Greetings, Why is there a c? Why is there a speed limit to the universe? Why is there a limit to how quickly a cause can follow an effect at distance? Why is there a "causality constant"? What is(are) the limiting factor(s) that make it what is? The speed limit is a consequence of what? Is...

What is the Relationship between Kepler's law and universal gravitation law? (IT HAS SOMETHING TO DO WITH THE CENTRE OF MASS)I know this; Newton's Law of Universal Gravitation F=mGM/r^2 derived Keplers Third Law r^3/t^2= constant: mGM/r^2 = mv^2/r gives GM/ (2pi)^2 = r^3/t^2. Read more...

Correct me if I'm wrong, but the only real evidence showing that the universe is expanding (and accelerating it's expansion) is by observing the so called "standard candle" supernovae which always have the same luminosity and observing that the farther they are, the more red shifted their light...

1. In an amusement park ride, passengers stand inside an 8 m radius cylinder. Initially, the cylinder rotates with its axis oriented along the vertical. After the cylinder has acquired sufficient speed, it tilts into a vertical plane, that is, the axis tilts into the horizontal, as shown in the...

Circular Motion and Universal Law of Gravitation Homework help! Homework Statement The passengers in a roller coaster car feel twice as heavy as their true weight as the car goes through a dip with a 30 m radius of curvature. What is the car's speed at the bottom of this dip? Given: r =...

Homework Statement 1. A typical white dwarf star, which once was an average star like our Sun but now in the last stage of its evolution, is the size of our Moon but has the mass of our Sun. What is the surface acceleration due to gravity on this star? (Msun = 1.99 x 10^30 kg, Rmoon = 1.74 x...

I'm having trouble with part a) of this question... [PLAIN]http://img69.imageshack.us/img69/5815/98157006.png So I started off by solving the DE above a), and I've gotten it down to: \frac{1}{2} m v^{2} = \frac{mgR^{2}}{(x + R)} + C I can tell I'm getting close, but I'm a little...

Yo. Wsup. I watched a video about three years ago where this guy suppossedly provedthe nonexistence of the universal set. I can't find it now but what he said (rather quickly) was that from Cantor, every set is a subset. Therefore, there is no universal set. 1) Is this valid? 2) RW...

First let me apologize for asking these questions. So much has been devoted to discussing the expansion of space both on the internet in general and this forum that the answers to my question are probably out there, but there is a lot to wade through. A lot. I found this forum and thought...

We just started on a chapter about gravity in my physics class. I'm curious about this: If two rings of different radius and masses of, say, 3 kg and 2 kg, are placed inside each other so that their centers of mass are extremely close (i.e. 1.0 x 10^-9 m) together, would the gravitational force...