Weird Definition and 482 Threads

Why can't our eyes focus on that one type of deep blue Christmas lights? It always appears fuzzy from a distance, even if another bulb right next to it appears in focus.

Edit: Nevermind, I figured it out! I jumped the gun in making this post. I'm doing another problem from Schaum's Outline: Basic Circuit Analysis. The problem, #3.24, and its solution are found in this...

Take a look at these videos: Smoke rings in air: http://www.swisseduc.ch/stromboli/etna/etna00/etna0005video2-it.html?id=14 Air rings in water: http://www.youtube.com/watch?v=bT-fctr32pE&feature=related Second one is really amazing, as it shows two things: - great stability of the ring, which...

Homework Statement There is an infinite slab of material with magnetic susceptibility \chi_m parallel to xy plane and between z=-a and z=a. There is a free current with density J=J_0 \frac{z}{a} in the x direction, so it's positive for z>0, and negative for z<0. What is the H field...

Homework Statement There is an infinite slab of material with magnetic susceptibility \chi_m parallel to xy plane and between z=-a and z=a. There is a free current with density J=J_0 \frac{z}{a} in the x direction, so it's positive for z>0, and negative for z<0. What is the H field inside...

Hi all,SUM of Series from n=2 to infinity of: 1 ------------ (2^n) (n-1) This question is driving me bananas... my tools are Telescoping or Geometric series, but neither seem to work: I've tried everything to get this into a geometric series form and then using the a/1-r formula, but...

I need to find the angle of a projectile after traveling x seconds of flight. I know the position of the projectile, the x seconds and the velocity. or I need to find the displacement of a projectile after a set increment time rather than the standard, total time used in the...

Homework Statement y''(x-1)-xy'+y=x2-2x+1 The Attempt at a Solution I don't even know how to start this, Don't know what substitution to do.

Hello, I got confused in my Classical Mechanics class (on a mathematical issue). So let L denote a function dependent on x and its derivative explicitly, such that its image is L(x,x*) (NOTE: I'm using * as the overdot-Leibniz notation for the derivative) and x is a function of t. To make...

Homework Statement i have the vector m(x(t), y(t)) = r = (s^t cos(t), e^t sin(t)) and want to find the line integral of itHomework Equations 1. \int m \centerdot r' dt 2. \int |m| |r'| dtThe Attempt at a Solution the answer is sqrt(2)/2 (e^pi - 1). when i do the problem the first way, i do not...

Homework Statement A hot air balloonist forgot to calibrate his altimeter before taking off. The altimeter displays his height as A*h (A being a constant multiplcator, and h is his real height). He does not know A, nor does he know the speed of sound. How can he find his height with just two...

I have two questions related to my experience. I don't know whether others experience it too. 1. Sometimes when I exert (force) with maximum capacity for an interval of time, I see Silver/Blue coloured moving micro-organisms in air. I feel slight dizziness at this time and this usually...

Ok, I admit it - I was a stupe. I took a bag of month-old frozen shrimp with me as I walked around my neighborhood about fifteen minutes ago while attempting to locate an apparently wild, but very beautiful dog. I didn't locate the dog. On the NW corner of our complex, however, a mountain...

Hi, I am doing this really crazy course at university, i need some help in understanding the final course mark calculation which is: Course mark = 0.6max{ T, F} + 0.4min{T, F} T = term mark = 0.3( average percentage on assignments) + 0.7( average percentage on term tests) F = final exam...

By watching a few moon landing videos on YouTube, i realized that the gravity on the Moon is not just weaker but act in totally different manner than gravity on Earth. This is one of many videos that shows the anomaly...What is wrong with this picture? link:

I have before theoretized about the idea if matter with a negative mass could theoretically exist, and what it's properties would be, acc. to the standard theories (GR). In fact you could argue for two kinds of models for this hypothetical negative mass matter, namely: model-1: anti-symetric...

Weird Transformer Problem :( Homework Statement "In the transformer shown in the figure below, the load resistance RL is 44.0 Ω. The turns ratio N1/N2 is 2.10, and the rms source voltage is ΔVS = 77.0 V. If a voltmeter across the load resistance measures an rms voltage of 26.5 V, what is...

Since 7, I always have a weird idea in mind As light can be in any colors, then why not black Later at 15, I understand that black = absence of (visible) light (photons) but would it be cool if we have a lamp that shines darkness? I once have discussed this idea with my physics teacher...

Recently, the MINOS detector has shown results that call into question the symmetrical properties of anti-neutrinos with respect to neutrinos: http://arstechnica.com/science/news/2010/06/antineutrino-masses-throw-physics-a-curve.ars More strange results came from MiniBooNE...

So I'm doing a summer homework assignment for AP Chem and I took normal honors chem last year so I know terminology and things like that, but this question in the summer homework assignment for AP Chem that I've been working on in the review-ish section of the book is not making any sense. I...

Radial distribution function -- weird result Dear all, I think I'm having trouble with my radial distribution function (RDF) calculation and would greatly appreciate it if anyone could give me some insight. I was testing my RDF calculation subroutine to get RDF for certain colloidal...

In class my professor for thermodynamics made the following deduction: We write dE = \left( \frac{dE}{dT} \right)_V dT + \left( \frac{dE}{dV} \right)_T dV And from the first law: dE = dQ - PdV * Equating and cancelling dE gives: (1) dQ = \left( \frac{dE}{dT} \right)_V dT + \left(...

Homework Statement A block, moving along a horizontal plank, is acted upon by a force of friction that is equal to 35% of the weight of the block. The block comes to rest from a speed of x m/s. Find x.Homework Equations v=u + at F=F1 + F2 The Attempt at a Solution I can't even attempt this...

Homework Statement Two related type of questions: 1) A rectangular prismic net enclosure for practising golf shots is open at one end. Find the dimensions that will minimize the amount of netting needed and give a volume of 144 m3. Netting is only required on the sides, top, and the far...

Dos this fractional Taylor series (a+x)^{-r} = \sum_{m=-\infty}^{\infty} \frac{ \Gamma (-r+1)}{\Gamma (m+\alpha+1) \Gamma(-r-n-\alpha+1)}a^{(-r-m-\alpha )}x^{m+\alpha} makes sense for x < 1 or x >1 and alpha being an arbitrary real number ..for example ?? , here a and r are real numbers ...

Anyone ever taken any of these weird "medications" ? http://en.wikipedia.org/wiki/List_of_psychiatric_medications This is a list of the names of some of them in alphabetical order, What happened if it applies to you?

Homework Statement A friend of mine tried to classify for the IMO a few days ago (he didn't do so well). A problem he had to solve was: f(x + xy + f(y)) = (f(x) + 1/2)(f(x) + 1/2) I didn't really understand what he said later. First he told me to find the values of X and Y for which...

The answer doesn't seem obvious to me: If I set up B_0 = 1 and B_n = n^2 Then let A_n = \sum_{m=0}^n B_m B_{n-m} = 2B_0 B_{n} + 2B_1 B_{n-1} + \ldots Then I almost expected A_n to grow like n^2. Instead, I'm getting (numerically) that A_n \sim O(n^5)! Why is that? In general, it seems that...

I assume a lot of strange stuff could happen. Is it possible for anyone to approximate the following probabilities? Walking through a wall. Walking on water for a minute. (Jesus for example) Dropping a ball but it goes up. A ball teleports 5 metres away. (I know all of it is...

Hi all, I'd like to write a story whose setting is a planet that is, on the one hand, hospitable to earth-like flora and fauna, while on the other hand being as different as possible from Earth in as many respects as possible. In other words, which parameters can I fiddle with without greatly...

Homework Statement Consider the Heat Equation： du/dt=k(d2u/dx2), where d is a partial and d2 is the second partial. The B.C.'s are u_x(0,t)=u(0,t) and u_x(L,t)=u(L,t), where u_x is the partial of u with respect to x. The I.C is u(x,0)=f(x) Now, consider the Boundary Value Problem...

I came across this weird graph from another thread: y=\left(x^2-6x+8+\sqrt{x^4-12x^3+52x^2-96x+64}\right)^2 It seems that there is a root y=0 for the domain x=[2,4]. I've never seen such weird behaviour on a graph before. How could analysis of this function (or not?) determine that there...

hi.. once again my thoughts bumped into weird energy question, yet, very basic... so say there is car, which mass is 1kg (yes, very realistic indeed), accelerating from 0 to 2 m/s. to viewer on the ground the energy at start was 0 and in the end 2J, the work done by the engine to the car is...

Homework Statement d20/de2+1=0 and the boundry condition is -d0/de(evaluated at e=+/- 1)=+/-H0(evaluated at +/-1). The final result yields 0(e)=(1/2)(1-e2)+1/H. What i don't understand is how to use this boundary condition and where the 1/H comes from. The Attempt at a Solution...

This might seem like a weird question, but I was just wondering about it. If a nuclear bomb were to go off in space, would it destroy satellites, the ISS, and everything else that's orbiting the Earth moderately close to the explosion? I'm not sure if the explosion would expand in a vacuum, but...

Hi, I'm reading an old book titled 'Mathematics of classical and quantum physics' by byron & fuller. It's quite nice, but some of the notation confuses me. On page 388, they're showing a simple differential equation: -i\frac{dy}{dx}=f(x) fine, but then they write the solution (given...

Hello people. I seem to have run into an odd problem with my page numbering. Whatever I do to the \setcounter{page}{#} command, it just won't let my first "real" page be number 1. Can you find the problem? Here is the code: \documentclass[10pt,a4paper,danish]{article} \usepackage{ucs}...

This is a suggested relationship between L/R and L L/R = kl + A/P P is the resistivity, A is the cross-sectional area and k is the constant for the circuit Using the value of the y-intercept find a value for P with the appropriate unit The graph of L/R against L had the intercept of...

Homework Statement The drawing shows four point charges. The value of q is 1.96 µC, and the distance d is 0.93 m. Find the total potential at the location P. Assume that the potential of a point charge is zero at infinity. Image of problem is attached. Homework Equations V=kq/r The...

Hey guys, That's my first post here, and I couldn't find any other place online where I can ask something like that and get rational scientific explanation. Here's what happened to me today and I have no idea what would cause it. I went to a coffee shop in afternoon to take a break from...

amazon.com sells items like milk, cookies, etc. i mean, the prices are equal or higher than what you would pay at your grocery store that's 5 minutes from your house. why would people buy this stuff online. also i was looking at a milk product i bought today. it was one of those milks...

the proof of second law of Newton for rotation goes like this: take a sphere rotating around some far axis FT=maT FT=m * ALPHA * R multiple by R tau = mR2 * ALPHA and we can say it true for every limit mass in a body. so sigma tau = sigma (mR2) * ALPHA sigma tau = I * ALPHA...

I'm fairly new to my readings in Quantum mechanics, so my apologies for any mistakes in interpritation of the theory. I've read that Einstein could not come to terms with entanglement and in general most entries describe it as a really weird affect, but it really doesn't seem that way to me...

So, a long time when I was little and fiddling with the ol baking soda - vinegar reaction, I had placed some baking soda, toilet paper, and vinegar into one bowl/dish and let it react and get the toilet paper all wet. Then (for an unknown reason) I electrocuted it with a 9V battery, sticking two...

Hi, I've got a tauon weak-decaying into a charged pion and a neutrino. The tauon has total energy \ E_{\tau} = 2.5GeV, rest mass \ m_{\tau} = 1.777GeV/c^2, and the pion has rest mass \ m_{\pi} = 0.1396GeV/c^2. This is everything I am told. I have to find the maximum energy the pion can have...

The average velocity v of an object moving through a displacement during a time interval. I understand what average velocity is. My question is what does it mean when an object moves THROUGH a displacement. I think I've seen this using angles as well.

we were requested to interface 8085 with memory and led,then a routine need to be written to make the led light up one at a time with delay 1 second.we have simulate the program and it run perfectly but when we test on the circuit we built it doesn't work.after a lot of trial and error,finally...

Homework Statement I need to calculate the integral: \int_{0}^{\frac{\pi}{2}}\frac{\sqrt{\sin x}}{\sqrt{\sin x}+\sqrt{\cos x}}\mathrm{d}x Homework Equations The Attempt at a Solution There is a tip: "try substituting y=\frac{\pi}{2}-x. I tried it and didn't get anywhere. I also tried several...

If you consider the vector function (expressed in cylindrical coordinates) \frac{1}{\rho} \hat{\phi} where \rho = \sqrt{x^2+y^2}, you notice it has a singularity at the origin ONLY. But if you express this in spherical coordinates, what you get is \frac{1}{r\sin \theta} \hat{\phi}, which is...

In the program below - #include<stdio.h> char places = 4; main() { char m = 3; short i; char counter[places - 2][1]; for(i = 0;i<=places-3;i++) { counter[i][0] = m; m++; counter[i][1] = i - i; } printf("%d \n", counter[1][0]);//Value of counter[1][0] = 4...