Formulas Definition and 522 Threads

Homework Statement Just wanted to find some clarity regarding this subject. In my textbook, it states that Q = nCvdT for constant volume and Q = nCpdT for constant pressure. However, one of the TA's in my classes were telling us how dU = nCpdT for constant pressure and dU = nCvdT for...

z_k=\sqrt[n]{u}=\sqrt[n]{r}e^{i\left(\frac{\phi+2k\pi}{n}\right)}, k=0,1,2,...,n-1 and z_k=\sqrt[n]{u}=\sqrt[n]{re}^\frac{\phi+2k\pi}{n}, k=0,1,2,...,n-1 Which one is incorrect (note that in the first, e is out of the root)?

1. 2. 3. 4. http://img176.imageshack.us/img176/7186/34581263.jpg 5. http://img87.imageshack.us/img87/8069/16289518.jpg 6. http://img291.imageshack.us/img291/5840/49412218.jpg 7. http://img809.imageshack.us/img809/8945/20137696.jpg 8...

What are usual tips in conjecturing formulas for math induction if I am given a certain sum of sequence? Thank you.

Homework Statement When do i use: (delta)Y=Viy+(1/2)ayt2 Compared to... (delta)Y=Viy-(1/2)ayt2 What tells me if I am going to be using (+) or (-)

Homework Statement I'm needing to write a program for thermodynamics, but before I can write the program, I need to find formulas for the heat capacity of a few substances: Al, Fe, BaTiO3, and Polyethylene. Ideally, I'm looking for equations that explain this behavior between 298K and 600K...

what determines what order the atoms in a formula are written? for example, why is it CO2 and not O2C? It doesn't appear to be ordered by atomic weight, place on the peridoic table or alphabetically so what is it?

I'm relativly new to quantum ohysics and have only read a few books, please can people explain some of the equations and the maths of quantum physics I can understand matrices and diracsc equations but please and somebody explain the maths of probability and other matters thx

Homework Statement I copied these formulas down that my professor had written on the board, but I have no idea how they may apply to velocity or acceleration. Homework Equations v=at+v0 v-v0=a(t-t0) v1=10(1)+0 = 10 m/s I believe that the 10 represents gravity, but don't...

Suppose f(n,p)=integral(n!/(x! (n - x)!dx, for x from -1/2 to p) where n>1, p<n+1/2 Are approximate formulas known for this kind of integral? Empirically, f(n,n+1/2) seems to be close to 2^n More generally, I'm looking for approximate formulas for integrals of n!/(x1!x2!...xn!) over nice...

So how did people like Einstein, and Newton really do it on a day to day basis? How do physicists really do physics? Is it a bunch of scientifically minded mathematicians sitting around doing lots of math until the results they get match experimental ones, or is it more a matter of doing...

Hello, it is mentioned http://en.wikipedia.org/wiki/Atan2#Definition" that using the tangent half-angle formulas it is possible to express the function atan2 as: \mathrm{atan2}(y,x)=2\mathrm{arctan}\frac{y}{\sqrt{x^2+y^2}+x} How can I derive this result?

Homework Statement The current in a 4.70 mH inductor decays over time according to the following function, where t is in seconds. I(t) = (.943A) e-(396 s-1) t) (a) What is the induced emf across the inductor at t= 5.00 ms? (b) How long does it take the emf to drop below 1.25 mV?The Attempt...

So I am trying to derive a formula from one of the standard summation formulas except starting at a different index. So if I have the series.. \sum i = \frac{n(n+1)}{2} Where "i" runs from 1 to n. (I don't know how to put it in the code.) If I want to make the series start from zero, I...

Sorry about that title, I had zero ideas what to put there. :smile: How important is it to learn the backgrounds/how the formulas came about in math and physics? Obviously you need a general understanding, but does one really need to know exactly how these formulas came about/work? Since that...

Does anybody happen to know where to find the perturbation theory formulas for the energies and states up to fourth order? I have to do a calculation up to this order and don't want to have to derive them if I don't have to (I know that Wikipedia has high order energies, but they only have the...

Can anyone give me the formula or equation so I can solve each of these? Homework Statement Question #1 Suppose the Sun is located 7.4 kiloparsecs from the center of the Milky Way galaxy, and that it orbits the galaxy at a velocity of 240 km/sec. Estimate the mass of the galaxy...

can some1 teach me some formula on how to relate power(mW/W) to sound(dBv/dBSPL)?i need some formula about this two topics and relate them because we are having a feasibility study on how to convert sound to electricity and we need some formulas,i know its kind a hard to transform sound to...

So I'm taking chemistry again after a five hear hiatus from the topic and I would really appreciate an explanation on a certain formula. magnesium +oxygen forms magnesium oxide Mg+O2=MgO My question is, what happened to the 1 of the oxygen atoms? Shouldn't it be MgO2?

I had to factorise this formula. The answer that I came up with is below: 6ax - 12ay - 18a squared. 6(ax - 2ay - 3a squared) My book says that the correct answer is: 6a(x - 2y - 3a) Would my answer have been marked wrong in an exam? Why is the book's answer preferable to mine...

Homework Statement Hello, could you please explain to me in simple terms how I can predict the chemical formula of the compounds produced when Group 7 elements are reacted with the elements in Group 1. Thanks. Homework Equations N/A The Attempt at a Solution N/A

i need help understanding compound names and formulas and charges of ions using periodic table

In 'AN INTRODUCTION TO SET THEORY' by Professor William A. R. Weiss, the following symbols are applied to the snippet below: ... The collection of formulas of set theory is defined as follows: 1. An atomic formula is a formula. 2. If ϕ and Ψ are formulas, then (ϕ ^ Ψ) is also a formula. ... I...

http://www.sosmath.com/trig/Trig5/trig5/trig5.html sum to product formulas part i am looking for a logical way of remmembering them

Homework Statement An electron microscope employs a beam of electrons to obtain an image of an object. What energy must be imparted to each electron of the beam to obtain a wavelength of 10.0pm? Homework Equations 1. E = hv=hc/lambda 2. lambda = h/(mv) 3. KE = .5mv^2 The...

Hi, all. I'm new with Matlab. Anyone knows how to write these formulas in Matlab? Homework Statement I need to write the following formulas in Matlab. The definitions are as follows. 1. p_{f}: the wireless link layer frame error rate 2. \tau: the wireless link layer inter-frame...

I wasn't really sure if this counted as homework because I need them in order to solve my homework problems, but since they're not my homework I'm putting them here. I need the six projectile motion formulas. I have ∆y=Viy∆t-1/2g∆t^2 (t squared) ∆x=Vix∆t I need the other four. I'd...

I was looking for help on figuring out the formulas for these questions on work and energy. Not looking for the answers, just the formula to solves these types of problems. 1. A box sits upon the floor. The box has a mass of 100. Kg. The coefficient of static friction between the box...

Question: A hot-air balloonist is ascending vertically at 1.8m/s during a burn. At the same time, a passenger drops an object from the balloon and notes that the object takes 15s to strike the ground. At what height is the balloon when the object strikes the ground assuming g=0.8m/s/s, no wind...

Homework Statement Given this formula Sum sin(a+b)=sin(a)*cos(b)+cos(a)*sin(b) prove this one Difference sin(a-b)=sin(a)*cos(b)-cos(a)*sin(b) Given this formula Sum cos(a+b)=cos(a)*cos(b)-sin(a)*sin(b) prove this one Difference cos(a-b)=cos(a)*cos(b)+sin(a)*sin(b)...

Homework Statement Two wires are tied to the 300 g sphere shown in figure. The sphere revolves in a horizontal circle at a constant speed of 6.50 m/s. What is the tension in the upper wire?What is the tension in the lower wire? Write an equation for the sum of the forces along y. Use it to...

Most of the texts I've seen (admittedly not a large number) which introduce the concept of relativistic momentum usually just pull a formula out of nowhere and then prove the formula must be correct. There is nothing technically wrong with this approach, but it's aesthetically unsatisfying, as...

Homework Statement I have been asked to prove e^{\alpha a}f(a,a^\dagger)e^{-\alpha a}=f(a,a^\dagger+\alpha), where a and a^\dagger represent the annihilation and creation operators of the quantum harmonic oscillator, respectively. Homework Equations The Attempt at a Solution The...

Hi, Given that the radius of a circle is X, and the side length of a square is Y, what is the maximum number of squares you can fill inside this circle, provided that the squares do not overlap? If you know of a general formula or something, can you please tell me the proof or give me a link...

Hello Forum, Using a fixed, Cartesian reference frame (i.e., we, observers, are stationary and located at the origin of the system), the trajectory of a particle would be easily described by the parametric (parameter time or arch length) equations [x(t), y(t), z(t)] or [x(s),y(s),z(s)]...

I much prefer putting all my work into a computer where I can see it and manipulate it rather easily post-facto. It is rather cumbersome to use word for this; is there any free program that allows copy-paste into word of fraction/intergration/limit/etc type stuff?

So its the beginning of chemistry and I don't know how to make formulas. BUT its very important I learn now otherwise I will have a very hard year... For ex: It says, "Fill in the correct formulas for the given anion and cation." SO2-4 and Al3+ (how do i combine those two to make a...

RE: Ocean Waves: 1. Linear Wave Formula - What is the average sea state that is capable of producing a 20 ft. wave? 2. Schoenbergers Wave Formula – What is the smallest average sea state that is capable of producing a 20 ft. wave?

Are more complex physics formulas, like those involving exponents, roots, logs, trig functions, etc., approximations to a certain degree? Are even simple formulas approximations? If so, what kinda precision: deci-, centi-, milli-, or better? Is there a regulated precision for new physics...

Homework Statement 13. Which expression represents an equality between accelerations? [SIZE="2"]A) Gme/r = v/r b) Gme/r2= v/r C) Gme/r2= v2/r D) √Gme/r= v/r2 The Attempt at a Solution i have no idea how to...

hello! im not very familiar with electromagnetic fields and classical physics, so i turn to you for help, a problem: assume you have a magnetic dipole in center (0,0) of a xy plane, i want to plot the vector of the field at an arbitary point on this plane,and to plot the filedlines, how do i...

Binary System Fg = G M1M2 / r2 M1d1 = M1d2 I don't have non-binary gravity formulas, so if you know any post them here (or any other algebraic gravity formulas you may be aware of) I am interested in algebriac formulas that define gravity and energy, but I am a bit skeptical...

Homework Statement a) Given: 2ad - Vf2 - Vl2 . Find Vl? b) Given: KE = 1/2 mv2 . Find V? c) Given: a= (Vf - Vl)/t Find Vl d) d= 1/2 gt 2 find t? e) ac= (mv2)r, find M? Homework Equations sorry, i do not know what are relevant eqs.The Attempt at a...

Hi P*e^(rt) = Accumulated amount of money Principal e logaritm rate time is for continuous compounding of rate. F=A(((1+i)^n-1)/i) and this one works for savings that are made frequently like every month or so but only with annual compounding of rate. is there any way to...

Suppose I give you a sequence of numbers such as 2, 4, 6, 8, 10... and ask you to find the next integer. You would probably tell me 12, because the sequence follows the rule 2n where n is the ordinal number. But if I told you the next number in the sequence is 42, your rule wouldn't work, and...

Homework Statement The maximum of 2 numbers x and y is denoted by max(x,y) and the minimum of 2 numbers x and y is denoted by min(x,y). Prove that max(x,y) = (x + y + l y - x l) / 2 and min(x,y) = (x + y - ly - xl ) / 2. Homework Equations The Attempt at a Solution Theorem...

Hello my name is Scott , I was trying to post a question , but after joining the physics forum - I think this site is for posting questions not finding answers until after posting it , so here we go. Maybe someone can answer this , at work I have a bet ( lunch ) on principles of...

Homework Statement (i) Combine Equations A and B to give a single equation for v and substitute this in place of v in Equation C. (ii) Rearrange your answer to part (i) to make r the subject of the equation.Homework Equations Equation A z = Δλ/λ0 Equation B v = zc For a planet such as the...

Hi, I was just confused as to the semi-structural formula nomenclature of -ene and -yne structures. The thing that I don't understand is the = sign in the formula. For example: CH3CH2CH=CH2 What does that equals sign mean? Does it represent where the double bond is located? If so...

I know that the electric potential for a continuous distributions of charge can be calculated using the following formula: Integral [ p(y) grad( 1/(|x-y)) d A_y ] Where grad represents the gradient of the vector function |x-y| and A_y is a area length element and p(y) represents the...