Periodic Definition and 437 Threads

Homework Statement A 1.50-kg, horizontal, uniform tray is attached to a vertical ideal spring of force constant 185 N/m and a 275-g metal ball is in the tray. The spring is below the tray, so it can oscillate up-and-down. The tray is then pushed down 15.0 cm below its equilibrium point (call...

Homework Statement Homework Equations How do you know when a given set of initial values for an ODE produce a periodic solution? The Attempt at a Solution I tried playing around with it for a bit and then searching the net but came up with nothing

Hi, I have a question that asks me to explain how you could know if the initial conditions lead to a periodic solution of an ODE but I have no clue right now. I'd appreciate any help. Thanks edit: The question is a bit obscure because I am not sure if they are asking in general of for the...

Homework Statement A particle of mass m is confined to move in one dimension. its wavefunction is periodic with period L\gg 1 - i.e. periodic boundary conditions are imposed. a)Determine the eigenfunctions and eigenvalues of momentum. Normalise the eigenfunctions on the interval [0,L)...

Hi, I'm looking for an efficient algorithm to solve this kind of equation : S = (1-\nabla^2)B where both S(x,y) and B(x,y) can both be non-periodic functions. We know S and want to find out what is B. I was wondering if there was a 'well known' method to solve this kind or problem in the...

Three parallel, infinite, uniformly charged planes are arranged as shown in Figure 24.32. (it looks just like it's described. The middle plate is positive sigma, the outer plates are both negative sigma.) Homework Statement A small hole passes through the middle plane. At t=0 an...

One thing that's always bothered me about Bloch's theorem is the periodic boundary conditions which are imposed on the system. Clearly, when dealing with an actual solid, the more natural choice would be to impose zero at the boundaries. I know that periodic conditions make the math easier, but...

Homework Statement Is the derivative of a periodic function periodic? Is the integral of a periocic function periodic? Homework Equations a function if periodic if f(x)=f(x+p) The Attempt at a Solution I think that the derivative won't be periodic but the integral will. I'm not...

If not, then what are the conditions for us to construct a periodic boundary condition(PBC)? If so, then please help me construct a PBC for the lattice shape in the attachments. I want to ask that what lattice site m's left neighbor is and what lattice site i's down neighbor is.From the...

in the periodic table we have the density of each element ( density(Si) = 2.33), density(O)=1.429). i wonder how we could calculate the density of SiO2 ?

Homework Statement The following specification of coefficients defines a Fourier series: a_{0}=\frac{2}{\pi};&a_{1}=\frac{1}{2};&a_{n}=\left\{\begin{array}{cc}-\frac{2}{\pi}(-1)^\frac{n}{2}\frac{1}{n^2-1}&\mbox{ for }n\mbox{ even }\\0&\mbox{ for }n\mbox{ odd}\end{array}\right.(\mbox{for...

Homework Statement What information can i find on the periodic table of the elements and what does it mean Homework Equations What is anything. The Attempt at a Solution Atomic symbol, the big letter, for the element abervation. The elements name, for the elements name. Atomic...

Homework Statement If a(t) is periodic and is composition of two signals such that a(t) = b(t) + c(t), then are b(t) and c(t) necessarily periodic? 2. The attempt at a solution I think that b(t) and c(t) must be! Is this correct?

Does anyone here know of a free periodic table (downloadable/printable) geared towards the needs of solid state? More specifically a table offering Lattice constants/crystallization systems, Mean Debye Temperatures etc. Ideally it would be a perfect copy of the periodic table featured by...

[b]1. I was given times for the sunrise in new york for one year. The question was that I needed to find a function that would best represent the data. The first column is the week number and the second is the time in hours and min. 1 7.2 2 7.2 3 7.18 4 7.14 5 7.09 6 7.02 7 6.54 8...

When I was in college years ago, I came across this test question: How will the periodic table of elements look like in another planet? Perhaps, it is asking for a general answer. Do you know if it will change the order of the elements?

Homework Statement Suppose that f(x) is a periodic function with period 1/2 and that f(2)=5, f(9/4)=2, and f(11/8)=3. Evaluate f(1/4), f(-3), f(1,000) and F(x) - f(x+3) (I'm not sure on this one, the teacher never really taught us this, we are on Derivative right now, but this is just one...

Hi all, I am new to this forum. My question is: Find values of b and r for which trajectories are attracted to a periodic trajectory. The function is: f(x) = r*x/(1+x)^b No proofs needed, just a numerical demonstration. Thanks a lot, Ljilja

Homework Statement For the periodic signal x(t)\,=\,2\,+\,\frac{1}{2}\,cos\left(t\,+\,45^{\circ}\right)\,+\,2\,cos\left(3\,t\right)\,-\,2\,sin\left(4\,t\,+\,30^{\circ}\right) Find the exponential Fourier series.Homework Equations Euler’s Formula...

I have the next problem. Let be the linear differential equation \dot x=a(t)x where a(t) is a periodic function of fundamental period T>0, a) Give two examples: where the general solution is a periodic function again and where the general solution is a non-periodic function. b) Show that...

Homework Statement If x(t) is a periodic signal with period T, show that x(at), a > 0, is a periodic signal with period \frac{T}{a}, and x\left(\frac{t}{b}\right), b > 0, is a periodic signal with period bT. Homework Equations HINT: Define x_a(t)\,=\,x(at) and...

Is there well known solutions to a differential equation \Big(-\frac{\hbar^2}{2m}\partial^2+U\cos\big(\frac{2\pi x}{L}\big)\Big)\Psi(x)=E\Psi(x)?

for the solution to the time-independent Schrödinger's equation with a period potential, V(x)=V(x+a) one has: \psi(x)=Af(x)+Bg(x) and \psi(x+a)=A'f(x)+B'g(x) the coefficients are related by a matrix equation, let v=[A, B]^T v'=[A', B']^T then v=Kv' where K is some non-singular matrix...

Homework Statement Use the periodic table to write the electron configuration of Gd. Homework Equations The Attempt at a Solution Gd has 64 electrons (atomic number 64) so I would assume that the configuration would be: 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f8 5s2 5p6 6s2...

Nowhere in my notes does it say what Eθ is and i can't find a definition of it on the internet :confused: I'll give you the context: For group 2 of the periodic table, state and explain the trends in the following for their elements: (i) redox property, related to Eθ value

has anyone ever memorized the periodic table?

Homework Statement Show cos²(x) is periodic The Attempt at a Solution I don't know how :confused:, could somebody please show me step by step? Thanks in advance! edit: I've got another show/justify question. If f is an odd function, then show f of f is an odd function. Whilst I...

i have two questions from kleppner's book, here it goes (iv'e attached a file which have the sketchs of the two problems): 6.17 A rod of length l and mass m, pivoted at one end, is held by a spring at its midpoint and a spring at its far end, both pulling in opposite directions. The springs...

Homework Statement Suppose f(t) is a periodic function with period T. Show that the Laplace transform of f is: L(f) = \frac{1}{1-e^{-sT}}\int_0^T f(t)e^{-st} dtThe Attempt at a Solution I started with the definition of a Laplace Transform for f: L(f) = \int_0^\infty f(t)e^{-st}dt Using the...

Hello I am stuck on the following question: Consider the following graph of a periodic function, period T. http://img157.imageshack.us/img157/4337/waveme4.png (a) Clearly giving the reasons, state whether this function is even, odd or neither. (b) With reference to all relevant...

Let me preface this by saying this is not a homework problem or anything, although it may look like it to some. Also, I don't have much of a math background (Calc I & II, Linear Algebra), but I don't think this problem requires much knowledge of "higher," math; just some good problem solving...

Given: x(t) = cos(2*pi*f1*t) 0 <= t < 4 cos(2*pi*f2*t) 4 <= t < 8 cos(2*pi*f3*t) 8 <= t < 12 f1, f2, and f3 are given as well Would it be possible to combine all three of these conditions into one convenient equation or am I just dreaming? I tried using Matlab to concatenate the three...

The tensile stress in a thick copper bar is 99.5% of its elastic breaking point of 13.0 X 10^10 N/m^2. A 500 Hz sound wave is transmitted through the material. (a) What displacement amplitude will cause the bar to break? (b) What is the maximum speed of the particle at this moment? Comments...

Analysis of the periodic sound wave produced by a violin's G string includes three frequencies: 392, 588, and 980 Hz. What is the fundamental frequency? [Hint: The wave on the string is the superposition of several different standing wave patterns.] The fundamental frequency is the lowest...

Out of KF, NaF, and RbCl, does NaF have the shortest ionic bonds as well as highest lattice energy, and RbCl have the lowest melting point? Thanks

I understand what the Fourier Theorem means, as well as how it behaves, I just don't understand how the math actually pans out or in what order to do what. I'm going to start off with what I know. f(x) = \frac{a_0}{2} \sum_{n=1}^{\infty}(a_n}\cos{nx} + b_{n}\sin{nx}) while, a_{0} =...

Let's consider the motion of a test particle in a central field. Is the Coulomb potential, 1/r, the only one that produces a periodic motion? If no, is there a condition for periodicity to occur? Thanks, Michel

how many elements are there in group 18?

The problem is this: A firework charge is detonated many meters above the ground. At a distance of 400m from the explosion, the acoustic pressure reaches a maximum of 10.0 N/m2. Assume that the speed of sound is constant at 343 m/s throughout the atmosphere over the region considered, that...

Are there any programs available for download that are the periodic table? I am looking for something I can keep on my laptop. Also, can any of you recommend periodic table posters (I am looking for comprehensiveness)?

I am trying to prove that if f(x) and g(x) both have period P, then f(x)*g(x) also has period P. What I tried to do was let f(x) and g(x) be represented as Fourier series f(x)=a_{0,1}+\sum_{n=1}^{\infty}\left[a_{n,1}cos(\frac{2{\pi}n}{P}x)+b_{n,1}sin(\frac{2{\pi}n}{P}x)\right]...

I'm designing an online periodic table of the elements and I have a question about the lanthanide and actinide families. I notice that all periodic tables put them below the main table, aligned with groups 4-18. Does this mean that they fit into those groups? Or is it just placed like that to...

Hello all. I have a quantum number question that is completely stumping me. "In another universe, the quantum number ml = 0, 1, 2, ... + 1. That is, the values of ml are positive integers, to a maximum value of +l. All other allowed values are unchanged, so the set of allowed values is: n...

My teacher gave us as excercices this: I'm pretty certain you have to prove it by contradiction, but I don't get how to represent to periodic decimal expension in a proof? Any hint is welcome, thanks in advance.

hey guys - just a question regarding a systems and signals course: if I've got two disctrete signals: x1[n] and x2[n] if i know both signals are periodic (individually) how do i prove the sum of these signals is periodic? requirement for periodicty (one signal): x[n+N] = x[n] where n...

I have yet another problem. Rodolfo paez plans to retire in 20 years he will make 120 equal contributions towards his retirement plan. 10 years after his last contribution he will be making 120 periodical withdrawals of 3500 a month until it reaches 0.the interest in the account is of...

The Janet Periodic Table of Elements (1929) seems more "consistent" than the modern form. The location of any element (row, column) is directly related to the quantum numbers of the most significant electron of the element. Please see; http://ca.geocities.com/chemguy777/index.htm

I can someone pleas help me with this problem? Thanks. A periodic function f has a period of 12. If f(7)=-2 and f(11)=9, determine the value of f (43) how do you do this?

Im working on a periodic table in vb.net and I want to start adding in the information for the density, melting point and boiling point for the elements. The problem that I am having is I need to find a source that I know has only entered these values for a specific temp and pressure. I prefer...

Why are there two rows separate from the general table at the bottom of the diagram? We just started chemistry this week and I'm interested in it, I might try to get it into an online course next year if at all possible, so I just felt like asking a question.