Demonstration Definition and 115 Threads

Someone can demonstrate me why ##Re(z) = \frac{1}{2} \left ( z+\bar{z} \right )## ##Im(z) = \frac{1}{2i} \left ( z-\bar{z} \right )## ##Abs(z)=\sqrt{z\bar{z}}## ##Arg(z)=-i ln\left ( \frac{z}{\sqrt{z\bar{z}}} \right )## ? 2# Is correct to affirm that ##Arg(z)=-i ln\left...

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 '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...

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...

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

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

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...

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...

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 [SIZE="4"]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...

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...

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...

Here is a nice demonstration of resonance and vibrational modes.

Hi, I'm going into a school for a day to help out with a science week and I've been asked to talk about mobile phones and electromagnetic radiation. The age range is 14-16 and its UK GCSE level. I'm trying to get ideas for practicals or interesting demonstrations to give, so far I've...

So, I need to create a physics demonstration that highlights a concept of introductory physics out of household items. Does anybody know of any good ones I could use?

Hi, I'm attempting to make a condensation cloud chamber to display alpha and beta particle tracks to a class of school kids as part of my placement. I get how it all works but I'm having real trouble with two things... 1) Finding a source of high purity alcohol. 2) Getting hold of...

Can anyone help me understand what's happening in this video? Is it a total bamboozle, or is there anything to it?

I'll preface this with the fact that I know nothing about math or physics, I'm not even sure this is a physics question. But I hope you all can help. A little background In 1966 Congress passed the federal Animal Welfare Act (AWA). Today the AWA regulates the commercial production of...

Now in LaTeX hope it's ok (the preview sucks): 1. Homework Statement given the integral I_n(r,z)= \int_z^r \frac{T_n(\frac{p}{z})T_n(\frac{p}{r})}{p \sqrt{r^2-p^2} \sqrt{p^2-z^2}} dp where T_n(x) is the chebyshev polynomial of the first kind: T_n(x) = 2 x T_{n-1}(x) - T_{n-2}(x) T_0(x)=1...

Here goes a theorem and its demonstration(attachment) .Sorry,I couldn't find it in english,so it's in portuguese). We have that the intervals In=[An,Bn] which are closed and limited. What I want to know is: what consideration(s) is/are NOT valid on the demonstration,when we consider an...

This link is to a truly amazing experiment involving sodium hexafluoride. I won't spoil it for you by explaining it, just click the link and see. It really made my day to see this. http://www.spikedhumor.com/articles/78239/Sulphur_Hexafluoride.html PS, there will be some 15 second video...

Hi, I have been working on this for a little while and think I am approaching it incorrectly. If someone can help, I'd really appreciate it. This is for a basic introductory calculus based Physics class that I am in. 1. Mathematically demonstrate the following equation with no numerical...