Example Definition and 879 Threads

Homework Statement Using the comparison test determine if the infinite series for sin(3/n^2) converges or diverges. The Attempt at a Solution Well... these are pretty straight forward, and it's pretty obvious that this is convergent, but I'm having trouble applying the...

Hi guys is the example true? what will the clock 3 count when the light reach it

I'm trying to follow a very simple example example in a text (Marion/Thornton example 2.1) and I think my rusty calculus is tripping me up and I'm just being stupid. I understand how to derive the acceleration down the plane: \ddot{x}=g\sin\Theta but next they say 'we can find the...

"If AB+BC = 24 and AB = 10, THEN 10 + BC = 24 is an example of the ? Homework Statement "If AB+BC = 24 and AB = 10, THEN 10 + BC = 24 is an example of the ? Homework Equations A) Symmetric property of equality B) Substitution property of equality C) Addition property of equality D)...

Example of transitive but not well ordered set needed! My question pertains to the definition of ordinals. According to Thomas Jech's edition of set theory, a set is ordinal if it is both transitive and well ordered by membership. I've been poking around trying to find an example of a set which...

Hi All, Thermodynamics forbids perpetual motion based in its second law, but how should one deal with an isolated H atom, seen here as a machine? Is there a concrete perspective of its stopping? In its stationary and fundamental state may one observe dissipation? Thank you DaTario

I'm trying to visualize the relativity example given in the book. The one with 2 generals signing a treaty at ends of a train (the light in the middle goes on and they both sign when light reaches them). The observers claim that one of the generals signed first. However, the generals claim that...

This is not actually a homework question, just something I am wondering about. A specified charge density dependent on /theta is glued over the surface of a spherical shell and you are asked to find the potential inside and outside the sphere, which is done in the example using separation of...

Hi there. I've been reading Brian Greene's book "An Elegant Universe" for the sake of curiosity and one of his examples to demonstrate special relativity really confuses me about the entire concept. To start, this is my current understanding of SR, so please correct me if I am wrong: -The...

Homework Statement A toy train moves along the track at 9.0m/s. When the power is turned off, the train comes to a stop in 6.0s. The net force on friction acting on the train to stop it is Homework Equations F=ma The Attempt at a Solution how do i find mass and acceleration so...

I know that the canonical example of a covering set of S^1 is R with the exponential map e^(ix) and that visually, this can be pictured by curling R up in a spiral and letting the "shadow" of the points determine the map. However, I want to know if this is another example: The covering...

It seems to me that the eyes are an example of the photoelectric effect at work. If so, which is more effective; current technology, photosynthesis, or our eyes?

I read that the outer measure is not countably additive, but I can only think of cases where the outer measure is countably additive. Can anybody give me an example where the outer measure is not countably additive? Thanks

Hey I am looking for an example problems that have piezoelectrics generating electricity. I would like to have and use a simple problem in which a piezoelectric is squeezed to generate electricity. Does anyone know where I can find such problems and solutions?

Consider a case where 2 people are in a car driving in a straight line at sufficient speed. At some point the driver takes an abrupt 90 degree right turn and owing to reasons attributed to Newton’s first law the co-passenger swerves into the driver (i.e. to the left). My question is why...

Hello all, I have been trying to fill in the gaps in the example of a functional given in chapter 3 of Hartle's book "Gravity" and I am not having much luck. I exhausted wikipedia for help to no avail. Does anyone know of or can provide a good simple example of a functional or just the...

What could be a real-life example (so no imaginary units and stuff :approve:) where the product of two elimentary functions of one random variable has a meaningful interpretation. Let's say I have a function that maps my random monthy income to number of days I can live off it and another...

This isn't really a homework question, can someone just explain this bit from wikipedia? consider the space X which consists of the union of the two intervals [0,1] and [2,3]. The topology on X is inherited as the subspace topology from the ordinary topology on the real line R. In X, the set...

Hi, can anyone give me an example of a bounded operator on a Hilbert space that has dense range but is not surjective? (Preferably on a separable Hilbert space) Im pretty sure such an operator exists since the open mapping theorem requires surjectivity and not just dense range, but its just...

I would like an example in Latex of a product with indices n=1 to N for bN, all minus 1, finally equal to bZ. I have not been able to find the original Latex tutorials.

I am math teacher and was asked the classic question, "Where am I ever going to use this in life" I usually have a real word example, but for the cosecant function I am stuck (Besides higher level math classes.) Anyone know a specific example?

So since I've started learning up on SR, the way I look at some things is nothing like it used to be before. The other day I was sitting down looking about, when I went cross eyed for a moment. Then I realized something quite interesting. If you have an object in front of you and you cross...

Ok from other posts, everyone seems to say that it doesn't matter if you stick vectors into a matrix via columns or rows. So i want to prove this to myself using an example from my notes. The only problem is, I get different answers. Can someone correct me? from my notes it says "show (0...

Homework Statement How do you draw a bode plot? I have a simple equation: H(S)=s+10 but no school book. Can you help me understand?

I'm a bit confused here with determining the tension of a rope. A very simple example will do in this case. Let's consider a weight of G hanging from a weightless rope which is tied to a ring hanging from the ceiling. The weight pulls down on the rope with the force of G and the ring pulls up on...

Here is a link to the text, chapter 9... page 30: http://books.google.com/books?id=gQ8LAAAAYAAJ&printsec=frontcover&dq=einstein&ei=tondSZLWOpnGywTa_pHyDg#PPA30,M1 So I have been analyzing this thought experiment from a causal perspective and have found it to be quite unsatisfactory. The...

In some discussions here about quantum effects in the macro world, ZapperZ will only admit that things like superconductivity, Bose Einstein condensates etc. are good examples. But these are just macroscpic quantum coherent phenomena. Of course, if you have a flux qubit, you can directly...

Homework Statement Give an example of a ring R and a function f: R---->R such that f(a+b)=f(a)f(b) for all a,b in R. and f(a) is not the zero element for all a in R. Is your function a homomorphism? Homework Equations Let R and S be rings. A function f:R----->S is said to be a...

Homework Statement If G is an abelian group, show that H = { a in G | a^2=1} is a subgroup of G. Give an example where H is not a subgroup. The Attempt at a Solution For showing H is a subgroup of G, hh' in G and h^-1 in G. (a^2)(a^2) in G also a = a^-1 in G so H is a subgroup of G...

Hey all - this is my first post so I mght as well say hi - I'm not very smart, but find everyday physics interesting. I tried to look up Newton's Laws, but I can't figure out: Is a dirt bike or bicycle a good example of the f=ma principle? All the info I found states that the force is...

hey guys, Any one can think of any examples ? Of a sequence of integrable functions{fn} on [0,1] that converges pointwise to a non-integrable function f:[0,1] --> R ??

I'm looking for a function f:[a,b] -> R such that |f| and f2 are integrable on [a,b] any helps?

I need someone to point me towards an instance of a relatively simple QFT problem which illustrates what can be calculated from QFT, how it is calculated, and its physical significance. (Note the qualification "relative". I realize there are likely no simple problems in QFT.) If someone...

Why is it that I can't describe with words the orientation of a 3D object (i.e. I can't give a set of angles that uniquely describe it). On the other hand, I can mimic fairly precisely it's orientation with my hand to describe it. A one dimensional object however, is easy to describe with an...

Homework Statement http://img266.imageshack.us/img266/152/78148531ur5.png Homework Equations A is symmetric. The Attempt at a Solution First of all if you calculate rT you'll get qTA so why it the order reversed in the picture above? Moreover I don't see why it is zero.

can anyone example a function that has limit just in one point

I'm having a hard time understanding example 5.8 in Introduction to Electrodynamics by Griffiths. Why, exactly, is Ienc = KL? It makes sense intuitively, but I don't see how to get this result explicitly -- shouldn't the line integral be along the y-axis, and since \bar{K}=K\hat{x}, shouldn't...

hi, I want to know the practical use of Integration and Differentiation. I know what it is. I just want to know how can i explain it with a practical example. example : for Differentiation - the dy/dx can be explained that y is dependent on independent variable x. How can d2y/dx2 be...

\lim_{x \to 0} x^(1/3) I know that \delta = {\epsilon}^3 the book gives an example: \lim_{x \to 2} (3x - 2) = 4 and you chose \delta = \frac{\epsilon}{3} so 0 < |x-2| < \delta = \frac{\epsilon}{3} implies |(3x - 2) - 4| = 3|x-2| < 3 (\frac{\epsilon}{3}) = \epsilon so i...

What's Example of Lebesgue Integrable function which is not Riemann Integrable?

Talking with a friend about the perpetual motion (we both know it don't exist but don't know how to prove it) I came with the following system. Say you have an almost empty magnet sphere. I say almost because at its center it has a little magnet such that it is repulsed by the internal walls...

Can anyone post me a clear example of how to compute the quotient space U/V from a vector space U and subspace V? I've seen many formal definitions but I'm a little stuck on practical use. I'm particularly interested in an example that shows how U and V being over the reals (for example) can...

Homework Statement I'm trying to develop an expression for the maximum accerlation of a person pushing an object up a slope. I've figured out an expression for acceleration using F = MA based on the forces acting on the person and the object. Now I need to find the max accerlation. We...

How close is this to what is being meant here? Let's say you have a big rubber sheet that can continue to stretch and stretch at the same rate and that it remains flat. (Yes a 2D analogy to help envision a 3D thing). On that sheet are little cars that move over the sheet. These cars...

I have: And how do I get the following matrix with elementary row operations?:

Homework Statement I have a matrix 1, 0, 1/12, 1/12 | 1/12, 0, 0, 0 0, 12, 143/12, 11/12 |-1/12, 1, 0, 0 0, 12, 143/12, 11/12 |-13/12,0,1,0 0, -12, -143/12, -11/12|-11/12,0,0,1...

example 3.30: Let the stress tensor components σij be derivable from the symmetric tensor field φij by the equation σij = εiqkεjpmφkm,qp. Show that, in the absence of body forces, the equilibrium equations are satisfied. I don't have any idea have to solve this problem. Can someone help...

http://img.photobucket.com/albums/v235/gsan_bot/magnetic1.jpg" Refer to example 6.2 shown in the picture, the magnetic flux = -1.2t and the deriative time of magnetic flux should be -1.2, thus, the flux is decreasing and the direction of the induced current should be reverse. but why it say...

Homework Statement Give an example of a convergent series \Sigma z_{n} So that for each n in N we have: limsup abs{\frac{z_{n+1}}{z_{n}}} is greater than 1

Homework Statement This is a worked example from Stewart's Early Transcendentals 6e section 2.7 p. 145 for anybody curious. Let f(x)= \frac{3}{x}. Find an equation of the tangent line to the hyperbola at point (3,1). Homework Equations m = \lim_{h\rightarrow 0}\frac{f(a+h) -...