Demonstration Definition and 126 Threads

Good morning, my name is Alberto and I'm from Peru (South America); and this is my first post on this forum. My Question is: A few hours ago I just discover an equation to obtain the values of the Beal Conjecture: A^x + B^y = C^z A, B, C has a common factor and x, y, z are coprimes, all of...

Hey guys! if anyone can help me I guess it is you! :) I'm trying to find the Fourier Series demonstration to continuous and periodic functions. I don't understand why people keep using X(jw) and X[e^jw] and even sometimes X(w) and X(f) If anyone can help me I'm really not understanding that...

Greetings, My questions below could be categorized into a mixture of “history of chemistry” and “experimental basis for chemistry”. I’m having difficulty phrasing the questions that I have, so I’m going to start by stating them as directly as I can, and then spend the rest of this post...

Homework Statement I'm asked to demonstrate that the electric potential is continuous over a surface with a charge density ##\sigma##. Homework Equations ##\Phi (\vec x )= \int _ S \frac{\sigma (\vec x' )}{|\vec x - \vec x '|}da'## The Attempt at a Solution I'm not sure what I must...

Homework Statement 'Show that row equivalence is an equivalence relation'. Homework Equations The definition for 'row equivalence' given in the text is, 'two augmented matrices corresponding to linear systems that actually have solutions, are said to be (row) equivalent if they have the...

Hello, I have two problems on an article about the demonstration of the jeans equation. I have 2 problems : 1*) Firstly, I begin with the collisionless Boltzmann equation : \dfrac{\partial\,f}{\partial t}+{\bf v}\,\cdot\,\nabla\,f-\nabla\,\Phi\,\cdot\,\dfrac{\partial\,f}{\partial {\bf...

I'm in the market for a large slide rule for my collection. If you know of an available one please let me know. http://albany.craigslist.org/wan/3460782750.html

Homework Statement Hello everyone. My problem is as follows: In a spontaneous process where two bodies at different temperatures T_{1} and T_{2}, where T_{1}>T_{2}, are put together until they reach thermal equilibrium. The number of atoms or molecules of the first is N_{1} and N_{2} for the...

I'm a high school physics teacher and I need a way to demonstrate net force = zero when something is moving at a constant speed. Usually some get it right away, some don't care and a few just really can't get their mind around it. I tell them about the parachutist, their car going 60 mph in a...

Homework Statement "Design an angular momentum demonstration. Back up your demo with a calculation(s)." I was given two cylinders with adjustable ball bearings inside, and will have access to an incline once in class (the cylinders are designed to roll down it). Homework Equations I...

Demonstrate that \sqrt{2}+\sqrt{3} is irrational. Thanks

Hello All, I hope I'm in the correct category, please let me know if I'm not. I'm looking for an applet on the web that I came across a few years ago. It demonstrated the basics of image compression by letting the user select from various transforms (DCT, some form of wavelet, a couple I...

Hi, This will be the last time I bother you with this for a little while. I have produced a rather amateur video (4min) of what I think handwriting recognition for maths should look like. For the time being, I have named it MathPen. http://users.ecs.soton.ac.uk/cmml100/VIDEO0012.mp4 What I...

Hi! I have to show that [L_i,x_j]= i \hbar \varepsilon_{ijk} x_k but my result is different, I'm definitely making a mistake :confused: ok I wrote L_i = \varepsilon_{ijk} x_j p_k then [L_i,x_l]= \varepsilon_{ijk} ( [x_j p_k , x_l] ) = \varepsilon_{ijk} ( {x_j [p_k , x_l] + [x_j...

Homework Statement Hello! My problem is with a variational expression. I have a quantity, say L, which could be determined by the ratio: K = \displaystyle \frac{\left[\int_a^b E(x)e_n(x)dx\right]^2}{\left[\int_a^b E(x)e_1(x)dx\right]^2} Where e_1(x), e_n(x) are known functions and n...

Is anyone familiar with Suarez's papers in this area? I've posted his most recent and pertinent papers on the topic below and even though I read them all, I'm still having trouble understanding his arguments: Single-photon space-like antibunching http://lanl.arxiv.org/pdf/1204.1712.pdf The...

Hi guys I know this limit goes to infinity lim (3^n-n) But how do I demonstrate it? Actually I know also that this type of limits goes to infinity lim \frac{a^n}{n^k},\forall a,k \in \mathbb{N},a>1 But I don't know how to prove it May you kindly help me? Many thanks

Homework Statement Demonstrate Analytically: If \lim_{x\to a}f(x)=L and L<0, there exists a δ>0 so that x\inDom(f), 0<|x-a|<δ \Rightarrow f(x)<0 2. The attempt at a solution I start identifying what I want to demonstrate and what are my assumptions. x\inDom(f), 0<|x-a|<δ \Rightarrow f(x)<0 I'm...

I have to demonstrate that if A^{rs} is an antisymmetric tensor, and B_{rs} is a symmetric tensor, then the product: A^{rs}B_{rs}=0 So I called the product: C^{rs}_{rs}=A^{rs}B_{rs}=-A^{sr}B_{sr}=-C^{rs}_{rs} In the las stem I've changed the indexes, because it doesn't matters which is which...

The YouTube video here will get you to think a bit. Basically, 15 separate pendulums that create various patterns: I wonder though if you could say how many given patterns are created. Not sure how to describe that... what do you think?

Demonstrations of Dirac equation covariance state: The Dirac equation is (i γ^{μ} ∂_{μ} - m)ψ(x) = 0. \ \ \ \ \ \ \ \ \ \ [1] If coordinates change in a way that x \rightarrow x' = Lx, \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ [2] where L is a Lorentz transformation, [1] should...

Hey, I am having a project in Physics, and the project is about interference in Waves. We got a task, and I need to demonstrate how waves interfere with each other. I got a demonstration with Lasers, how they split up, but I also need a much more simple demonstration. Something like when...

I'm going to give a presentation involving mathematical proofs to people who are not really into math (in a Critical Thinking class). I would like to use something from Euclid's elements. I would like it to be a geometric proof - but what is the most "audience friendly?" I need to be able...

I found this great demonstration video of quantum levitation and just had to share it. http://www.youtube.com/watch?feature=player_embedded&v=Ws6AAhTw7RA

1. We have A\subseteq \mathcal{U}. For i_1, i_2 \in \{0,1\}and A^0 := A^c, A^1 := A. A is a complete set if A\cap A_1 ^{i1} \cap A_2^{i2} \neq \emptyset then A_1 ^{i1} \cap A_2^{i2} \subseteq A Demonstrate that A_1, A_2 are complete sets too. And if A is a complete set then A^c is a complete...

Dropping a strong magnet in an aluminum tube is cool, but what will happen if magnets are dropped at the same time in tubes of aluminum and glass that are adjacent? Or at a defined distance due to strength of the magnets? Somebody probably has thought of this and demonstrated the results. It...

When I try to demonstrate that lim (x^2)=4 x--->2 I found a different delta (delta=min{2-sqrt(epsilon-4),sqrt(epsilon+4)-2}, towards the one that is written in Demidovich´s book (delta=epsilon/5). Could someone help me? Could someone tell...

Are you confortable with the demonstration in page 19 of Introduction to Modern Cosmology - A. Liddle ? My problem is in particular eq. (3.4) when he writes the potential energy of a test particle. I think there is a factor of 2 missing in the denominator.

Homework Statement Suppose that f=f(x1,x2,...,xn) is a homogeneous function of degree r with mixed partial derivative of all orders. Show that Can this be generalized? Homework Equations We say that a function f is homogeneous of degree r if there exists r such that f(tx1,tx2,...,txn) = tr...

¿Is this demonstration of the book from Ernst Mach correct? I am reading the book "The science of mechanics", Ernst mach. He is talking about the achievements of Christian huygens, and he wants to calculate the centripetal acceleration of a circular motion. As you can see in the image...

Homework Statement I have a doubt about the steiner theorem demonstration, its actually trivial, but I can't realize why is this. Lets see, the demonstration which you can see http://en.wikipedia.org/wiki/Parallel_axis_theorem" goes as follows: I_{cm} = \int{(x^2 + y^2)} dm I_z = \int{((x -...

Interesting four minute video with a magnetic levitation superconductor train http://www.youtube.com/watch?v=5el1A5B-h3Q&feature=player_embedded Perhaps a good demonstration for teachers

HI, I will not used the template provided since this is not a textbook problem. It's a problem I have with a demonstration in Quantum Mechanics Vol 1, Cohen-Tannoudji " Complement C III [Q,P] = i \hbar Consider the ket: |\phi \rangle = (Q +i\lambda P)|\psi \rangle where \lambda is an...

Having trouble using the bernoulli equation to work out the dynamic head for this experiment. the equation I am using is as follows: P1/ρg+(v1^2)/2g+z1=P2/ρg+(v2^2)/2g+z2 Where: P= static pressure v = fluid velocity z = vertical elevation of fluid so z1 = z2 for horizontal tube...

Homework Statement I have some doubts about the demonstration of the differentiability. If I'm asked to proof that an average function is differentiable on all of it domain, let's suppose its a continuous function on all of its domain, but it has not continuous partial derivatives. How should I...

I'm conducting a seminar at college on application of AC to passive components. To Demonstrate what inductive reactance is , i want to wind a coil , connect it to a DC source , find the resistance. Then i want to directly connect it the AC mains and find th effective resistance again and show...

I watched MIT OCW PHYSICS 8.01 lectures, and in lecture no.13, i saw a puzzling demonstration. Link :http://ocw.mit.edu/OcwWeb/Physics/8-01Physics-IFall1999/VideoLectures/detail/embed13.htm" I don't understand, what can be the reason for the oscillations of ball on the track with the...

For my lab class we have to make some sort of physics demonstration in our machine shop with a budget of ~$600-$1000. I was wondering if anyone on here had some suggestions as to some cool/fun things to make? Things along the lines of Van De Graaf generators, inverted pendulums, etc. can be...

Homework Statement You attach a strong rope or steel cable to a light pole and a car parked on a downhill incline. If you have a student lift, pull, or push perpendicularly on the rope in the center it will be easier to move the car than if you were to push it. Why? Prove this...

I'm not sure if this has been discussed before. We all know about the Monkey Hunter Demonstration. Assuming a uniform gravitational field, a projectile shot directly at a target will strike the target as long as the target has zero velocity at t=0 and both the projectile and target begin...

I would like to demonstrate an identity with the INDICIAL NOTATION. I have attached my attempt. Please let me know where I made mistakes. Any suggestion? I am trying to understand tensors all by myself because they are the keys in continuum mechanics Thanks

Hello all, While searching for a holiday gift for a younger sibling (who is rapidly becoming interested in the sciences), I remembered a demonstration from a high school physics course that sparked my own interest in physics. It involved a unique object - a light bulb with a needle and 4 black...

I was pondering a posible global warming demonstration. Two identical clear cubes with thermometers in the center. they have some 1 way valve at the top. Put dry ice in one. The one containing the dry ice is initally cooler, but as all of the dry ice evaporates, the cube fills up with CO2...

The demonstration: A mass of 2kg is hanged to a string that is hanged vertically from a fixture. Another string is attached to the bottom of the mass and then this bottom string is given a downward pull. Note that the strings used are assumed identical. This demonstration can be found here...

Tueseday, I go to Auburn to interview for an open position in Alabama Science in Motion. http://www.auburn.edu/academic/science_math/cosam/announcements/ Basically, I would be traveling around high schools, moving equipment, doing demonstrations, and developing new labs. I need to come...

My second PHP question this week...:smile: I'm writing a PHP app which includes things such as form validation and database interaction. So far, almost everything has been written procedurally. However, I started playing around with PHP's OO stuff, and it's cool. Problem is, this app is being...

I am a graduate student working in semiconductor physics. I have been asked to give a presentation to high school girls about my field. The problem I am running into is that the organizers would like me to provide something hands-on that the girls can do relating to semiconductors. I have not...

I have heard the demostration in Greece via news of press. but the news from world-wide press are not correspond to common sense. because press make money from advertisement of corperation, they are apt to disguise reality. I think only death of one boy can not provoke such situation...

In my last class the professor had a bike tire with a string attached to its axle. When the tire was hung from the string it sat parallel to the floor; however, when it was spun and hung from the string it remained perpendicular to the floor and rotated around the string. What was it that kept...

Several years ago, I was at a science/art exhibit in Los Angeles where a box was on a pedestal and it had a couple hundred jellybean sized light bulb-type things in it. They appeared to be just a filament in a glass encasement. When they were just sitting in the box, they were dark, however...