Strange Definition and 566 Threads

Hi all, I was working through a chapter on Lagrangians when I cam across this: "Using a Taylor expansion, the potential can be approximated as ## V(x+ \epsilon) \approx V(x)+\epsilon \frac{dV}{dx} ##" Now this looks nothing like any taylor expansion I've seen before. I'm used to ## f(x)...

What's up people? I'm new in this wonderful forum. I have several questions about circuits, and they are not really common, I mean, I find them somehow complicated, but I would really come to enlightenment if you guys gave me some clues. 1.- So, let's suppose we got the simplest circuit, a...

Homework Statement Hello! One of the easiest rules (when possible to apply) to factor a quadratic is to find both x-s by x1 + x2 = b x1 * x2 = c Homework Equations Please, take a look at what is written in the book. I can't grasp why x1 = -2 and x2 = 3, and not, as I thought, x1 = -3 and x2...

I know that all the quark names have a meaning and that the strange quark was named "strange quark" because it had strange properties.What are those strange properties the strange quark possess?

Homework Statement The wavefunction ψ(x,t) obeys the time-dependent Schrodinger equation for a free particle of mass m moving in one dimension. Show that a second wavefunction φ(x,t) = ei(ax-bt)ψ(x-vt , t) obeys the same time dependent schrodinger equation, provided a = ħa2/2m and v = ħa/m...

I read that a wave function of the photon does not exist in coordinate space. But, when I read Feynman's "QED: the strange theory of light and Matter", for instance, when the photons travel through the glass, it seems like wave functions of photons. How it is with this?

I was crunching through some logarithm questions for homework when I noticed this. I was wondering if any of you have any incite on what causes these two numbers to be exactly 1 unit apart from each other. I found it very odd, and I am wondering if there is some kind of relation here that I am...

DISCRETE STEPS IN DISPERSION MEASURES OF FAST RADIO BURSTS (emphasis mine) And no, this wasn't published in April 1st! Link to New Scientist article: Is this ET? Mystery of strange radio bursts from space. Garth

I am in an independent study working through probabilistic graph theory and I am stuck on part of a theorem from chapter 4 of The Probabilistic Method by Joel Spencer and Noga Alon (specifically theorem 4.2.1). In this context, $p$ is a prime number. The part where I am confused comes from a...

Something strange regarding the 1904 plane (Flyer No 2) built by the Wright Brothers I am looking for an as simple as possible mathematical model that can explain how it really worked. In 1904, the Wright Brothers started to test a new plane, Flyer II, somewhere near Dayton, Ohio where they...

For the parametric equations x = t^3 - 3t and y = t^3 - 3t^2 I got that the graph has a vertical tangent when t is = to postive or negative one. And it is horizontal at t = 2. However, this implies that at the point (x,y) = (2, -4) the graph has both a vertical and horizontal tangent. How...

Hello again, I've got another trouble with a new differential equation: (x^2+2)y'''-(x^2+2x+2)y''+2(x+1)y'-2y=0 I did a try using matrices(file is attached), however the system to be solved is hard to compute. Do you have any idea to help me solve this out?

Hi What makes kaons strange apart from the fact that they have strange particles in them? Thanks

I have done large amounts of research and could not find any books, sites or forums of how the strange matter in strange stars is formed. I know that the process of the formation of the strange star carries out mostly like the collapse into neutron stars and quark stars but how do these strange...

Hello, everyone I've trying to solve this integral but it seems like the methods I know are not enogh to solve it. So I'd be glad if you could give me some trick to get into the answer. Here it is: Thanks in advance!

Homework Statement I want to find the partial derivatives in the point (0,0) of the function f:\mathbb R^2\rightarrow\mathbb R f(x,y):= \begin{cases} 0 & \text{if } (x,y) = (0,0) \\ \frac{y^5}{2x^4+y^4} & otherwise \end{cases} Homework Equations Our definition of the partial derivatives in...

Do someone knows what this dot "." means? I just know this notation [001]. Thank u Abigale

Homework Statement We have experimented on rolling cylinders and have gotten the function for a rolling cylinder but have gotten a strange constant from experiment. Homework Equations t = 2\sqrt{\frac{l}{g}(1+\frac{r}{R})\frac{1}{\sin{\theta}}}-0.5 The Attempt at a Solution Is this constant...

Hi, I have a question that came into my mind while solving some problems. If I have a constant times an expression in a square root like ##4\sqrt{16}## I can square the constant and push it into the square root: ##4\sqrt{16}=\sqrt{4^2 16} = 16##. But what if the constant outside of the square...

My son "invented" a simple board game. It consists of a series of squares numbered 1 to 32. You start at square 1, then advance your piece according to the throw of a die, until square 32 is reached, and you win. Nothing else happens, and the only difficulty is that square 32 must be reached...

I have tried to use the intrinsic' fraction' function in Fortran but have failed to understand how it works. I thought that it would return the fractional part of a real number, but when I ran a few numbers through it, I got something that was a far cry from what I expected. For example, I...

1. Write ∫e^(-t^2)dt with 0<=t<=x , as power series around 0. For what values of x this series converge ? attempt at a solution: f' = e^(-x^2) => f'(0) = 1 f''= -2x*e^(-x^2) => f''(0)= 0 f'''= -2e^(−x2) +4*x^2*e^(−x^2) => f'''(0)=-2 I tried to find a general rule for the derivatives but with...

Hi, I have just encountered a strange (for me) inconsistency with a derivative: If I take the x derivative of ##\frac{x}{x+a}## I get ##\frac{x+a-x}{(x+a)^2} = \frac{a}{(x+a)^2}##. However, when I take the integral of the latter I get: ##-\frac{a}{x+a} (+constant) ≠ \frac{x}{x+a}##. I have...

The problem Adam is saving 1, 5 and 10 dollar bills. Adam has 165 bills. The amount of one dollar bills is twice as high as 10-dollar bills. The total value of his savings is 735 dollars. How many 5-dollar bills does Adam have? This problem was translated. Sorry for grammatical errors. The...

One of our cats, we have four , has acquired the habit of chewing pipe lagging to bits, and the same cat has started catching Earth worms at night and leaving them in the kitchen.

I was recently reading the strange world of classical mechanics. It prompted me to calculate some round trip times for things moving near the speed of light (classically, with an aether). I found that the predictions it makes are awfully similar to relativity, and I can't think of an experiment...

Homework Statement Suppose a 2x2 matrix X (not necessarily hermitian, nor unitary) is written as X = a0 + sigma . a (the sigma . a is a dot product between sigma and a) where a0 and a1, a2 and a3 are numbers. How on Earth does X represent a matrix? it's a number added to another number...

I'm taking (undergraduate) Nuclear Physics this semester and while it's going well the kind of comments and attitude I'm getting from my professor confuse me. He dismissed Kenneth Krane's Nuclear Physics book when I told him I was studying from it. When talking about the Dirac equation and Pauli...

Object A goes horizontal line and object B diagonal line in 45 degrees angle (Fig 1). A and B have the same velocity ##v## in x-direction. In y-direction, B has velocity ##v##, A has none. The magnitude of ##v## is not very important, but the total speed of B must be below ##c##. In their own...

After working a homework assignment which required sketching effective potential energy for the gravitational/coloumb forces, I went and looked at a few effective potentials for inverse cube and inverse quartic (not sure if this is the right word; 1/r^4 force) forces, with inverse square and...

Homework Statement Find electric field anywhere on the x-axis due two two point charges Q at (0,0,d) -Q at (0,0,-d) Homework EquationsThe Attempt at a Solution AttachedSomehow I am not getting the correct answer. I reviewed my steps with 4 people and we could not find the error! I'm...

Homework Statement One of the following equations represent a possible decay of the K + kaon. K+ → π+ + π0 K+ → μ+ + νμ State, with a reason, which one of these decays is not possible.The Attempt at a Solution At first i thought the first decay was not possible, however, i recently learned...

Hey! I'm new here and I just wanted to ask a question and maybe I'll come back here once I have started college in a week or so. :P But firstly I must say, at first I thought the confirmation question for signing up was a science question about acid and I was totally stumped. But that's PH... I...

I have a ligid MS Office 2003 with excel. I have this loaded on my newer computer and had been working until a few days ago. All of a sudden, I cannot change what I typed in the file anymore. I restarted the computer, I uninstalled the Office 2003, then reinstalled the whole thing again. It...

So when i use the following command, I get the following error DSolve[y'[x] - y[x] == 3, y[x], x] DSolve::deqn: Equation or list of equations expected instead of False in the first argument False. >> But when i change the variable y[x] and y'[x] to s[x] and s'[x], It works why is this...

These two coins are strange because the probability between their heads and tails can be adjusted from 0% to 100%. What is the probability of getting two heads or two tails, if for example one coin is set to flip heads 70% and the other to flip heads 20% of the time? Thanks.

I have a long tube (aout 30 cm) with a convex lens of diameter 7.5 cm on the one end and a small hole of diameter 2 cm on the other. When i shine a light through the hole and let it pass through the lens, i get a flowery pattern on the wall, looked very strange to me. There is a maxima in the...

This confusion is about the following problem: Suppose the entire region below the plane z=0 is filled with uniform linear dielectric material of susceptibility ##χ_e##. Calculate the force on a point charge q situated a distance d above the origin. Now, this problem is done in Griffiths'...

I have some experimental data (not hypothetically, this is real data), which has a downward sloping shape. A sharp decrease initially, before settling to what looks almost like a downward linear slope. To investigate further, I decided to take the base 10 log of the y-axis data. The...

So the question reads: A spaceship is accelerating at 1000m/s^2. How much force is required from the backthrusters to completely stop the spaceship? In space, nothing truly stops. You may not be accelerating but you are definitely orbiting something (planet, moon, sun, etc). We can put...

Help!Strange problem with scientific calculator. I was doing chemical equilibrium problems where one of the steps required me to square the reciprocal. Which was (1/4.2x10^52)^2 The correct answer for this is 5.7 x 10^-106 but my Casio FX 115 ES calculator keeps showing zero. Can anyone...

I have been looking at material properties such as thermal expansion of metals which usually involves very small coefficients. The general equation of thermal expansion is usually L_\theta = L_0 ( 1 + \alpha \theta) where L is the length and theta is the temperature change. The coefficient...

I'm trying to evaluate floor heating systems for installation in my new studio, and I have to admit that my thermodynamics is a bit rusty... But I came across the following, and I could use a sanity-check. Basically, it's an in-slab heating element that claims to be 2.5x "more efficient"...

I was sitting by a camp fire this weekend and I noticed that the snow/ice around the fire was melting in a strange way and I couldn't think of a good reason as to why it would leave this pattern. Essentially, it looked like small icicles all aimed towards the fire, almost parallel to the ground...

Hi, last semester I did a project with two fellow students. We made a numerical model to calculate the reflectance from a periodic V-shaped structure of silicon similar to this: In the course of doing so, we came across something we could not explain. I have placed an image of it below...

I was playing my old pinball machine today when the display started to malfunction. After several minutes, the dot matrix display shows only a horizontal stripe as shown below. The interesting thing is that when I move my eyes vertically over the horizontal stripe on the display, I am able to...

Homework Statement Two boxes each mass 10 kg are raised 2.0m to a shelf. The first one is lifted and second one is pushed up a smooth ramp(frictionless). If the applied force on the second box is 50N, calculator the angle between the ramp and the ground Homework Equations n/a The...

Quite late this afternoon I noticed a series of perfectly formed circles of light on the wall above my computer. Where are they coming from I wondered? Putting my hand in front and tracing one back the window, then climbing onto a chair it was clear they originated from the little holes at the...

Homework Statement The problem is shown below. Homework Equations Conservation of momentum? pi = pf ∫Fdt = I ? The Attempt at a Solution This question is really strange. I have started to do this question for many hours and I don't know how to start it. I have tried to list...

Okay, so I am trying to figure out how in the world my professor evaluates our final grade for the course and it is a rather strange and confusing method. I need help figuring out how to calculate my grades thus far so I can see what I will need to make on the final. Here's what he has in the...