Weird Definition and 469 Threads

Hi, Is there any solution for the following problem: Ax = \lambda x + b Here x seems to be an eigenvector of A but with an extra translation vector b. I cannot say whether b is parallel to x (b = cx). Thank you in advance for your help... Birkan

Homework Statement Two blocks A and B are connected by an ideal rope R, both blocks lie on a horizontal surface S. The coefficient of static friction (\mu_s = 0.30) and kinetic friction (\mu_k = 0.20) between the blocks and the surface S are the same for both blocks. The mass of block A is m_A...

In reading https://www.physicsforums.com/showthread.php?t=67979,#7", I was drawn to MIH's entry, about boiled peanuts I like boiled peanuts too (pronounced balled)! Just made a pot of them yesterday.. Mmmmmm good eatin' :approve: I put my raw peanuts in salt water(1/4c Kosher salt per quart...

Homework Statement Find the integral of sqrt(9-x^2) over [0,3]. You will not be able to find an antiderivative, so instead interpret the definite integral as the area of a region and compute the area geometrically (I haven't reached integration by substitution and integration by parts in class...

Homework Statement I need to find the average acceleration of a gramophone record. Initial angular velocity, W = 0 Final angular velocity, w = 3.50rad s^-1 angular displacement, 8 = 0.25rad Homework Equations The equation given by the answer is t= 8/w a = ( w - W ) / t the answer is 49.0...

I was just reading some story about how Kathy Ireland is opposed to abortion because at the moment of conception they have a 'DNA Fingerprint'. Abortion issue aside, it got me to wonder: If I sequenced my mother and father's DNA and generated all the 2^23 permutations of chromosomes would my...

So I talk to a professor about an undergraduate position in his lab (I'm in my second year) and he accepted me, got me a scholarship, and even offered me a fellowship for the summer if I am available during the summer. But it seems that he is always busy and did not arrange for me to meet with...

A few nights ago, the pole on the side of the road that holds our transformer snapped, the transformer exploded and set the pole on fire. In my plant we were running on 2 out of 3 phases for a while until we completely lost power. Now here's the "weird" thing... Just about every motor...

In my lab we're doing some stuff with logic chips and d-flip-flops and in our kit of circuit components are a couple of these red plastic covered strips that have about 12 pins coming out. Their some kind of resistor strip but question is how do you use them? do you just consider each 2 pins...

http://www.mirror.co.uk/2009/04/09/weird-easter-traditions-from-around-the-world-115875-21266238/

Hello, I came upon this strange integral: \int \frac{f(x,y)}{x}dx How would one attempt to solve this? Would integration by parts do?

Homework Statement If A = [ -4e^4t sin(9t) -4e^5t cos(9t) ] [ 4e^4t cos(9t) 4e^5t sin(9t) ] then what would A^-1 be? I think I am mainly confused with the cos's and sin's...and all that other junk...since I know how to get the inverse of a regular matrix! Thank you...

a weird function i guess... Homework Statement P(x) is an increasing function and Q(x) is a decreasing function in interval a ≤x≤b. Another function γ(x) satisfies m≤γ(x)≤M. Find m and M in terms of P(a), P(b), Q(a), and Q(b) if: a. γ(x) = P(x) . Q(x) b. γ(x) = [P(x)]2 – [Q(x)]2...

Homework Statement Show that the group Z/<(a,b)> is isomorphic to Z if gcd(a,b)=1. Find generators of Z/<(a,b)>. 2. Relevant information Please note that the question is asking for Z/<(a,b)>, not ZxZ/<(a,b)>. I am having trouble understanding the meaning behind <(a,b)> as a subgroup of...

Homework Statement \displaystyle\int\left(\dfrac{\ln x}{x}\right)^2 dx 2. The attempt at a solution I tried letting u=\ln^2 x and dv the rest and I also tried dv=\ln^2 x dx and u the rest. It won't work out.

Homework Statement This problem asks you to compare two values and say whether one is greater, they are the same, or the problem does not give you enough information to answer the question. In this question they give you a symbol, in this case "+" and then define what it does to a number...

A weird collision "theorem" All -- Many moons ago I thought I heard a professor refer to a "theorem" in mechanics which stated that if a hard object is released from an infinitesimal height above a hard surface, the force will be exactly twice the weight of the object. Did I hear...

Homework Statement solve: y" + 4y' + 4y = (3 + x)e-2x ... (1); y(0) = 2 & y'(0) = 5 Homework Equations using Undetermined Coefficients Method The Attempt at a Solution solving the associated homog. eq of (1) : y" + 4y' + 4y = 0 ... (2) we get: yc = c1 e-2x as m=-2 let...

I'm getting this weird LaTex bug that is really messing with my posts. Sometimes when I use the tex tags, I get this weird problem that no matter what I put inside them, the post will always display the a certain equation inside of the tags. For example: I am trying to edit my signature...

Either I am going flippin crazy or something big just happened and I need an explanation. So I'm sitting at my computer watching a chill movie. Just 5min ago two flashes of a greenish blue light occurred outside my window. The light was apparent, it wasn't sort of there, it was there and...

It is alleged that in Australia that a man attempted to pay a bill with a drawing of a spider (you can read all about it here: http://news.ninemsn.com.au/article.aspx?id=665847 ) Does anyone have any similar stories to share about customers trying to use odd forms of currency?

Homework Statement Let y_{n} = 1 + \frac{1}{2} + \frac{1}{3} + ... + \frac{1}{n} - \int_{1}^{n} \frac{1}{t}dt Prove that the sequence \{y_{n}\}_{i=1}^{n} convergesHomework Equations The Attempt at a Solution y_{1} = 1 y_{2} = 1 +\frac{1}{2} - \int_{1}^{2} \frac{1}{t}dt = 1 + \frac{1}{2}...

Homework Statement I can not determine the solution to the diff. eq. Homework Equations \ddot{x}+k \cos{x}=0. The constant k is postive. The Attempt at a Solution I tried solving it with the methods I know and it all ended up in a big mess. I am just not used to the second...

Im in 2nd year now...and I've been worrying about really trivial things but its been driving me crazy ... and I've been getting really good marks with no trouble but I've been thinking about How do I know what to do Like When I substitute into an equation ... SOmetimes I use...

Homework Statement There are five positive integers x1,x2,x3,x4,x5 such that: \sqrt{x1-1}+2\sqrt{x2-4}+3\sqrt{x3-9}+4\sqrt{x4-16}+5\sqrt{x5-25}=x1+x2+x3+x4+x5 Fine the possible value of: \frac{x1+x2+x3+x4+x5}{2} a) Data insufficient b)55 c)110 d) I couldn't exactly remember this...

Homework Statement Homework Equations Trig identities or straightforward derivative? The Attempt at a Solution Is the answers 1. C 2. B 3. A 4. D I tried taking the derivative of these, but a friend of mine here told me it deals with trig identities and isn't...

Homework Statement f(x+y)= f(x) + f(y) + y*x^2 +x*y^2 Given: lim of f(x)/x where x approaches 0 is 1 Find : 1) f(0) 2) f ' (0) 3) f ' (x) Homework Equations The Attempt at a Solution countless hours with other coursemates that lead to nothing...

Hi Folks..I came up with a weird looking DE for my research Q''[t] = f[t]Q'[t] + g[t]Q[t] + h[t]*Sqrt[(Q[t])^2 + (k[t]Q'[t])^2] The thing that mixes my mind is the square root term..If there is no square root terms it would like a riccati type..but there is..i tried to google it but it...

http://www.alexisparkinn.com/weird_aviation_videos.htm scroll down to bottom of page for video. Are these models? impressive looking.

Hi, I'm going into 2nd year as a math major ...In the last week I've been thinking consciously about how if an algebraic property is written in terms of x ...then it applies to x^2 ,x-2 x^3, etc . Like: sin(2x)=2sin(x)cos(x) Implies sin(2x^2)=2sin(x^2)cos(x^2) I know this without...

There are these two homework questions that I think are asking the exact same thing, yet use different equations (and get different answers for them) First Question 1. Homework Statement A potential difference of 10V is present between the plates of a capacitor. How much work must be done...

Hey I was doing a standard derivative problem but I ran into something somewhat strange. Check it out: \frac{d}{dx}\sum_{i=1}^xx=\frac{d}{dx}x^2=2x Okay, simple enough..but what if I write it like this? \frac{d}{dx}\sum_{i=1}^xx=\frac{d}{dx}(x+x+...+x)=1+1+...+1=x. Why am I getting two...

Homework Statement A man hanging upside down is holding a partner who weighs 565 N. Assume that the partner moves on a circle that has a radius of 6.50 m. At a swinging speed of 4.40 m/s, what force must the man apply to his partner in the straight-down position? Homework Equations I'm at a...

Is it possible to injure your neighbor with microwaves using the heater of a microwave oven when there is a thick wall yours and your neighbor's apartments? I know this is a really weird questions, but that's because it's related to a really weird situation. A friend of mine does not get along...

a weird "spherically symmetric" metric Minkowski metric in spherical polar coordinates [t, r, theta, phi] is ds^2 = - dt^2 + dr^2 + r^2\,(d\theta^2 + sin^2(\theta)\, d\phi^2). The question is what happens when the coefficient of the angular part is set to constant, say 1, instead of r^2...

I'd like to see whether weird reciprocal sums of integers in the form \sum_{x\in S}\frac{1}{x}, where S is some unconventional set of integers, converges or diverge. Does anyone know any? For example, \sum_{x\in S}\frac{1}{x} where S is the set of integers that, when expanded in binary...

I have this line in a Fortran 77 program, and I don't understand how it works: nran(i)=mod(int(i*ranw(Idum)),i) + 1 What I don't understand is that nran is not a function, nor is it dimensioned anywhere (its type is implicitly an integer). This line only works if it comes right after the...

When you solve something and it gives answers like this: {σ -> 0.653831, μ -> 9.31514, γ -> 7.22386}, how do you get it to give {0.653831, 9.31514, 7.22386}, i.e a set without the symbols? Cheers,

does anyone know how to derive multivariate taylor series in mathematica? by default it is computed in a very strange: "Series performs a series expansion successively with respect to each variable. The result in this case is a series in x, whose coefficients are series in y. "

One question I've been focusing on lately is sound. Can any of you help me understand how it is created or why we even hear it. It just seems a little weird how two objects can makes sound, or even one in some cases. Are the particles or what? I don't know.

Right now I am working with: PMT: Hamamatsu R928/0115/0381 PMT Power Supply: McPherson PMT Power Supply Model # 7640 O-Scope: Tektronix TDS 5104 Oscilloscope PMT Housing: PhotoCool Housing PMT Housing Power Supply: PhotoCool Power Supply Input: 200 mW 532 nm ND:YAG laser I have...

FOR PICTURE of CIRCUIT: community.webshots.com/photo/2479536900103460081IWuFAY A wheel consiting of a large number of thin conducting spokes is free to rotate about its axle. The brush makes contact one spoke at a time. There is a uniform B field pointing into the page. The wheel is...

Homework Statement I have a capacitor which i just like a plate capacitor, but instead of the upper electrode being a plate it is a point charge Q. the lower plate is held at a fixed potential V=0. I am supposed to calculate the capacitance of the capacitor. The Attempt at a...

Homework Statement A parabolic communications antenna has a focus 6 feet above its vertex. Write an equation for the parabola and find the width of the antenna 9 feet from the vertex. Locate the origin strategically. Homework Equations y= x^2 (parent equation for parabola) The...

Hi! As you can see, I didn't use the template, but that is because this is a different kind of question. I need to think of a project relating to physics for my final project in Honor's Physics. She (the teacher) would like an idea by Monday and the sooner I can start researching, the better...

if we had that A_{i,j,k,l} is a set of number could we obtain for the integral \int_{-\infty}^{\infty} dV e^{-A_{i,j,k,l}x^{i}x^{j}x^{k}x^{l}} = C |A_{i,j,k,l}|^{-b} here C and b are real constant, i am looking for a quartic or similar analogue to Gaussian integral, but can be defined as...

why is that sometimes I get small bumps on my knee and leg every time I wakeup every morning, my bed are all covered in foam so its impossible to bump my feet into it. all bumps occurred on different locations and sometimes happened every morning more often. kindly explain this tnks.

Homework Statement I'm working on a quick problem regarding a presentation that I'm giving, but I've come across an issue that I can't seem to resolve. Namely \displaystyle \left. \frac{d}{dt} \right|_{t=0} f(\phi^p (t+t_0) ) = \left( \phi^p \right) ^\prime (t_0) f Does anybody see...

Homework Statement Estimate the maximum speed of a horse. Assume that a horse is 1.8 m tall and .5 m wide. Homework Equations The Attempt at a Solution This problem is from the work & energy chapter in my book. However, I can't figure out the relevance of the dimensions of the...

Homework Statement a projectile of mass M explodes into three fragments while in flight at velocity v. one fragment of mass M/2 travels in the original direction, one of mass 3M/10 comes to rest and the third fragment of mass M/5 travels in the opposite direction. The energy released in the...