Weird Definition and 469 Threads

  1. S

    Projectile Motion: Finding Angle and Displacement in x Seconds

    [SIZE="4"]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...
  2. D

    Second Order ODE with Weird Coefficients: Solving the Equation x2-2x+1

    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.
  3. N

    Understanding Partial Differentiation in Classical Mechanics

    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...
  4. W

    Weird Dot Product Homework Q: Unusual Answer?

    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...
  5. D

    Height equation in a weird way.

    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...
  6. Z

    Medical Weird Experience: Questions on Silver/Blue Micro-orgs & Sensation

    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...
  7. mugaliens

    Goodness, THAT was weird Mountain Lion encounter

    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...
  8. S

    Schools Weird marking scheme for university course -

    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...
  9. C

    What causes the strange gravity effects on the Moon?

    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:
  10. heusdens

    Here is some weird idea: Dark matter/energy explained by negative mass matter

    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...
  11. R

    Solving a Problem with Transformer Load Resistance and Source Resistance

    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...
  12. S

    Is it possible to create a lamp that shines darkness?

    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...
  13. S

    Weird Results from Neutrino Experiments

    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...
  14. C

    Weird bouyancy/mass/density problem

    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...
  15. J

    Radial distribution function - weird result

    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...
  16. N

    Entropy & Enthelpy - A Weird Deduction from Class

    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(...
  17. P

    What is the speed of a block sliding on a plank when it comes to rest?

    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...
  18. A

    Optimizing Dimensions and Cost in Golf Net and Fencing Projects

    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...
  19. Z

    Weird Expansion: Fractional Power Series

    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 ...
  20. J

    Medical Anyone ever taken any of these weird medications ?

    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?
  21. G

    Internat. Math Olympiad exercise. Weird function.

    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...
  22. R

    A weird convolution (recurrence relation)

    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...
  23. O

    Weird Probabilities: Is It Possible?

    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...
  24. onomatomanic

    How to design a weird but comfortable planet

    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...
  25. T

    PDE-Heat Equation with weird boundary conditions help

    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...
  26. Mentallic

    Weird Graph Behaviour - Analyzing a Root in Domain 2-4

    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...
  27. M

    Energy, once again weird unclear thing

    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...
  28. M

    Weird question about Nuclear Weapons

    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...
  29. F

    What do the primes mean in this differential equation?

    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...
  30. K

    LaTeX Weird page numbering problem in LaTeX

    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}...
  31. D

    How Does the Y-Intercept Help Calculate Resistivity in an L/R vs. L Graph?

    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...
  32. B

    Electric Potential problem, 4 equal charges, different signs, weird shape.

    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...
  33. R

    Medical Why did my heart beat make the numbers on the screen look like ripples in water?

    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...
  34. M

    Weird second law of Newton for rotation

    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...
  35. J

    Quantum entanglement, not that weird.

    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...
  36. R

    Why Does Baking Soda + Vinegar + Toilet Paper Turn Blue?

    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...
  37. N

    Weird words. Someone please clarify.

    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.
  38. P

    Solving 8085 Weird Problem with DCX/DCR Instruction

    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...
  39. L

    What is the Integral of a Trigonometric Function with a Weird Substitution?

    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...
  40. A

    Weird singularities/cylindrical & spherical coordinates

    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...
  41. D

    Weird response from statement in c.

    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...
  42. F

    How is entanglement not weird ?

    How is entanglement not "weird"? https://www.physicsforums.com/showthread.php?t=321682&highlight=entanglement+socks" But explain to me how this is not weird: So 2 people receive a set of boxes, all the boxes are numbered and the 2 sets have the same numbers, the boxes have 3 doors, opening a...
  43. B

    Medical Unusual tolerances and weird reactions.

    i know no one can diagnose me on here, I'm just looking for opinions and maybe guidance to things to research. my body has a strange way with medicine. 98% of the drugs I've taken (legal and otherwise...) don't work as they are supposed to. i usually have to take a double or triple dose to...
  44. Borg

    Taste the Unusual: Weird Food Combinations

    Some very unusual food combinations. Just don't look on a full stomach. http://thisiswhyyourefat.com/"
  45. S

    Is this weird? Squaring Numbers.

    I'm 16, still in high school. I consder myself pretty smart, but today I think I met one of the smarter people in my life. He's 14 and rides my bus. He scored ~10 points higher than me on a math test (i got 273, he got 285 I believe, not sure). I knew this, so I mentally ackknowledged that he...
  46. P

    Finding angle X when given an inequation and a weird equation

    Homework Statement sin (x) + sin (2x) + sin (3x) = 0 http://www4b.wolframalpha.com/Calculate/MSP/MSP531196eg6ff0edb8i9400000gb08c7ag3hfbfeh?MSPStoreType=image/gif&s=8 Sorry for not following the recommended layout, it's just that this question boggles me and I don't know any relevant...
  47. L

    Does Curry's Paradox Prove the Existence of the Flying Spaghetti Monster?

    Curry's paradox can be used to (dis)prove the riemann hypothesis and string theory, and even prove the (non)existence of God... no, actually, Curry's paradox IS God. :biggrin: Just kidding... I am now (speaking somewhat hyperbolically) freaked out. Does Curry's paradox go like this (try "1 =...
  48. D

    Summing Weird Series: A Basic Understanding

    I have a rudimentary understanding of integration as it applies to finding the area under a curve. I get the idea of adding up the areas of progressively smaller rectangles to approach the area, and that at an infinite number of rectangles the areas would be exactly the same. Right now I'm just...
  49. G

    Microsoft's Natal Video: Video Games Getting Weird?

    http://www.viddler.com/explore/Joystiq/videos/1118/ Wii is coming out with the motion plus and Microsoft has a new device which provides somekind of a virtual reality experience ... now I am not an avid gamer but the first impression that I am sensing from the Natal video is that it seems...
  50. S

    Would a school find it weird for a student to have transfered twice?

    My brother went to a community college this past year and was accepted into a state university for the coming fall. However, this state university does not have as good of a program for his field as another university in the state, so after the coming year he would transfer out of that...
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