Derive Definition and 620 Threads

You have 10 days of numbers that are averaged together (10 day avg). The most recent 3 days of numbers also averaged (3 day avg). The 3 day average is divided by the 10 day average to arrive at (3d/10d) The oldest number in the series is dropped off and a new one, X, is added. X is the newest...

given some complex model that does not generally have analytic solutions why do we search for, and solve for, cases where there are analytic solutions? considering at this point much simulation can be done using numerical methods on computers what is the point? take for example a pendulum...

i'm not sure if this is the right place but I'm trying to get my head around derive 6 and i have a couple of questions that don't seem to be coming out right... d^{2}y/dx^{2} + 8dy/dx + 16y = (4e^{-4x})(sinx+cosx)^{2} ; y(0)=y'(0)=0 so i inputed DSOLVE2_BV(8, 16, (4·^(-...

hello, can someone look at my problem and tell me how to get to the arrow? thank you so much.. i am studying for my midterm and i have no clue where it come from. thanks

A rock with mass m = 3.10 kg is suspended from the roof of an elevator by a light cord. The rock is totally immersed in a bucket of water that sits on the floor of the elevator, but the rock doesn't touch the bottom or sides of the bucket. Here is the part that I am stuck on: Derive an...

As we know, the variational principle can be used as the fundamental principle of mechanics. Without knowing Newton's laws, the Lagrangian could be derived from symmetric consideration. As the simplest case, the Lagrangian of a free particle could be derived from Galileian invariance, or the...

I have been asked to write down the taylor expansion for two concentric spherical surfaces with radii r1 and r2 of a lens and mirror combination which I think is called a Mangin Mirror. It is supposed to be related to the x and y-axis positions. Also, I have been asked to derive the...

[Ignore]How to derive magnitude of Electric field to this? Homework Statement My book states that |E| = \frac{2kQ}{d^2} = 2\pi k\sigma I thought k, the coulomb constant is \frac{1}{4\pi\epsilon0} Homework Equations The Attempt at a Solution

Homework Statement Hi all, I need help with deriving a third order accurate scheme for the inhomogeneous equation u_t + a u_x = f based on the approach used to derive the Lax-Wendroff scheme, that is, replacing the time derivatives of u by space derivatives of u. The Attempt at a...

Homework Statement Hello All, I'd please like some help in deriving a 2-phase 3-dimensional partial differential flow equation from first principles. Homework Equations I know that the starting point is Darcy's flow equation. The Attempt at a Solution A key step is substituting...

Greetings all, My first problem: I have been asked to derive the minimum radius ratio for coordination numbers 4 and 6. I read the book and looked at the sample problems, but they do not help at all. I realize that it has to do with the geometry of it, but have no idea how to use that. The...

Derive Kepler's Third Law of Planetary Motion from Newton's Law of Universal Gravitation. I know the Law of Universal Gravitation is Fg = (Gm1m2)/(r^2) and the Third Law of Planetary Motion is T^2 = kr^3 What should I do next?

Sum of all Forces= Force - Force of Friction We have Formulas to use in our physics test for an object on an inclined plane w/ friction: Sum of all Froces= F-Ff, Sum of all Forces=ma, a=(Sum of all Forces)/m Ff=Uk(N) and Sum of all...

I am new to Derive 6 and Laplace Transforms. Is it possible to solve the closed loop gain A/B of the attached loop using Derive 6. If it is possible, can someone guide me through the steps using Derive, as the problems that lie ahead will be much more complex, and I want to use Derive in the...

I need to derive the expression for the gradient operator in spherical coordinates. I know the following R =sqrt(x^2+y^2+z^2) theta, call it %, = arctan sqrt(x^2+y^2)/z phi, arctan (y/x) Using dT/dx= dT/dR*dr/dx+dT/d%*d%/dx+dT/dphi*dphi/dx, do partial derivates... dR/dx =...

please show me explict calculations

I'm still a intermediate science student. I'm not understanding how to derive the ohm's law. can anyone help me?

Homework Statement Ok I'm trying to derive a=v^2/r Homework Equations The Boas book gives me two equations to start off with: r^2=\vec{r}*\vec{r}+constant and v^2=\vec{v}*\vec{v}+constant The Attempt at a Solution Where the hell did those equations come from. I know...

hi, i just learned about lagrange multipliers and i am very confused about how to derive and use them. another thing, how would you use them to find points on a surface that are closest to a given point outside the surface

I got some precalc review to prepare for calc, and after hours of doing the packet, I'm on the last problem set...but it's all about derivatives which we never touched on last year. Homework Statement I'm supposed to derive sin^2 + cos^2 = 1 Homework Equations It says to use cos 0...

Well the question is in the title. Does Malus' Law (http://en.wikipedia.org/wiki/Malus%27s_law ) follow automatically from Maxwell's equations, or is it really an extra thing put in by hand? In particular I'm interested if there is a purely classical electromagnetic explanation (i.e. without...

If an equation has the form c = A + Bt - Ct^2 + Dt^3 + Ez Where A,B,C,D and E are known constants, t and z are the variables. t=15 and z=2. Derive an algebraic expression for delta_c/c in terms of delta_z/z and delta_t/t. Apparently you are suppose to calculate delta_z, delta_t and...

How can I derive the equation from a Graph? The x coordinates are: 28,30,32,33,34,35 The Y coordinates are: 7,8,9,10,11,12 We could express this as a relation, r: r{(7,28), (8,30), (9,32), (10,33), (11,34) (12,35)} Regards, Gordon,

URGENT x 10 DERIVE a 6x6 Hamiltonian for bulk semiconductors Okay here is a little challenge for you guys. Try and test your skill a little. First 10 people to properly derive a 6x6 Hamiltonian for bulk semiconductors will gain bragging rights in this forum.

Homework Statement basically what the topic states - derive the formula for the derivative of arctan x. Homework Equations d/dx (arctan x) = 1/(1+x^2) The Attempt at a Solution strange question because we already know the answer. but I am not sure how to start this. i know...

I have to prove that tan^(-1)(z) = i/2 * log[(i+z)/(i-z)] Homework Equations sin^(-1)(z) = -i * log[iz + (1-z^2)^(1/2)] cos^(-1)(z) = -i * log[z + i(1-z^2)^(1/2)] The Attempt at a Solution I've tried a number of attemps. I first tried the most obvious and I did sin^(-1)(z)...

Homework Statement Find a,b,c, and d such that the cubic f(x)=ax^{3}+bx^{2}+cx+d satisfies the indicated conditions. Relative maximum (3,3) Relative minimum (5,1) Inflection point (4,2) Homework Equations The Attempt at a Solution I am so lost as to how to do this :/...

Homework Statement The reaction: CO + Cl <-> COCl2 has the rate law: rate = k[CO][Cl2]^(3/2) Show that this rate law is consistent with the mechanism: Cl2 <-> 2Cl (fast) Cl + CO <-> COCl (fast) Cl2 + COCl -> COCl2 + Cl (slow) (i don't know how to do superscript and subscript on...

Given a(t) = -Cv^2(t) where C is a constant, express v(t) and x(t) as explicit functions of time t. Assume v(0) = v0 So I tried integrating both sides of the equation to get: v(t)+C' = -C integral v^2(t) dt but then I how am I supposed to integrate v^2(t) dt... Also, I thought I could do it...

pleasezzzzzzzzzzzzzzzz

Hey folks, I really need help setting up a canonical ensemble. I am using the einstein model and have an energy: E_\nu=A + \sum_{i=1}^{2N} \hbar\omega n_i+\sum_{j=1}^{N} \hbarh\omega n_j where A is some constant. Now, I need to build the partition function which I 'think' looks like...

in a recent paper in am.j.phys. an Author claims that he derives the addition law of velocities based on time dilation and length contraction. my oppinion is that time dilation suffices. what is your oppinion?

For a triangle with sides a,b,c and its corresponding circle with radius R: \frac{a^2b^2}{c^2} +\frac{a^2c^2}{b^2}+\frac{b^2c^2}{a^2} \geq 9R^2

I have a system of two PDEs: y_t+(h_0v)_x=0 \quad (1a) v_t+y_x=0 \quad (1b), where h_0 is a constant. Then I want to show that (1) has traveling wave solutions of the form y(x,t)=f(x-ut) \quad (2a) v(x,t)=g(x-ut) \quad (2b), where u is the propagation velocity...

Question 1: A ball is dropped from the top of a building and it strikes the ground with a speed of v m/s. From ground level, a second ball is thrown straight upward with the same initial speed of v m/s at the same instant that the first ball is dropped. Ignoring air resistance, determine at what...

THe Question asks 'Derive the entropy of an ideal gas when its molar specific heat at constant volume is constant.' So I've taken \Delta S = \int_{S_0}^{S} dS = \int_{T_0}^{T} \frac{\partial_S} {\partial_V} dT + \int_{V_0}^{V} \frac{\partial_S}{\partial_V} dV in this context what...

Hi, The kinetic molecular theory of ideal gasses is a topic that we have to study in both our Physics and Chemistry syllabus. A part is deriving the kinetic gas equation PV = \frac {1}{3}mN<v^2> froom the postulates of KMT. However, of the 3 Physics and 2 Chemistry textbooks I've...

I would like to derive gamma(v), by starting with the galilean transformations for x and x'. Knowing that t=t'=0, if a light pulse is emitted at the origin of S then the ratio t'/t should somehow be eliminated from the two equations. From there, one can obtain gamma(v). Any ideas?

Pls derive the time-independent schrodinger equ from the time-dependent equ.? Thanks! Anyone has any sugestiond on how to approach this? -\frac {\hbar^2} {2m} \frac {\partial^2 \psi(x,t)} {\partial (x)^2} + U\psi(x,t) =i\hbar\frac{\partial\psi(x,t)}{\partial (t)}

Hi, I am very eager to know how to derive e=mc^2. I am sure that you all would be knowing how to derive the world famous equation E=mc^2.i know the basics but still it is a tough job to explain that. But I am hoping that you would send me a reply as soon as possible. Thank you

DJGriffiths, 3rd ed., Prob 1.37: derive the \hat{r}, \hat{\theta}, and \hat{\phi} unit vectors in terms of \hat{x}, \hat{y}, and \hat{z}. I know the formula and how to find them, but derive them?? ...unless this is what is meant? tia, -LD

i know that that the limit of this expression is e, but i don't know how to derive it... i will be really grateful if someone could help me solve this problem

I'm taking cal 2 right now and i missed the part in cal 1 where he talked about "log theorem". Now this guy tells us that he's lazy when he corrects exams and if we don't use the log theorem to derive a term then he won't correct that term. I've looked on the net but couldn't find explanation or...

Hello, I have very interesting physics problem. But i really have no idea how to solve it... Maybe somebody can give me some useful hints? Here we go: "Air drag (air resistance, drag) is a resisitvie force which is the result of a moving object colliding with air molecules. Dervie the drag...

In the same way that it is possible to derive most trigonometric identities from the addition formulas, what is the way that the difference of sines and cosines formulas were derived, such as \sin{a}-\sin{b}=2\cos{\frac{a+b}{2}}\sin{\frac{a-b}{2}} thanks, I am trying to avoid as much...

A question that I've spent hours on, but still can't seem to extract friction from it: 10.) A flight attendant pulls her 70.0N flight bag a distance of 253m along a level airport floor a a constant velocity. The force she exerts is 40.0N an angle of 52.0 Degrees horizontal. Find the...

How do you derivate this: x^(x/8)=4x Can anyone help?

Does anyone know a website that will derive the force from different spring configurations, i.e. two springs in series with different spring constants. I would just like to be able to understand and work with any combination of springs: two in series, connected to 3 in parallel connected to one...

The forumula for 2¶r can intergrated to make ¶r^2 (at least I think). So can anyone derive the volume of a sphere 4/3¶r^3?

I'm asked to derive the mathematical expression for the erlationship of centripetal force as a function of T, m, and R. I've found, from data, that F=0.615/T^2 = 0.05m = 1/4R how would I bring it all together to form one equation involving T^2, m, and R? Any help, thanks.