Parameters Definition and 489 Threads

Homework Statement Compute the following parameters of the final image formed by the lens system shown in the figure below a) position b) size c) nature (Real, Virtual, Upright, Inverted, Etc.) Homework EquationsThe Attempt at a Solution i am kind of lost at where to begin...

Let ##\mu: \mathbb{R}\to \mathbb{R}##, ##f: \mathbb{R}\to \mathbb{R}##, and ##r: \mathbb{R}\to [1, \infty)## be bounded measurable functions (which may be discontinuous). I'm interested in the function ##v:\mathbb{R}\to\mathbb{R}## given by ##v(x) = \mathbb E \left[ \int_0^\infty e^{-\int_0^t...

Hi, I've defined engine power requirements based on driving dynamics, but am not sure how to extend this to engine parameters. From design requirements, I've fixed my gear ratios, and hence can determine how much power and torque is required from the engine at a particular speed. I want to then...

Hey guys, recently I have do some self-study on the ground response parameters on cohesive and cohesionless soil.. I made some deduction but I cannot confirm if it is correct or not, thus needing the help from the PF community. The deduction is as follows; I need explanation for the occurrence...

I am trying to develop a Ventury https://www.physicsforums.com/javascript: Pump using Compressed Air a d Motive Fluid and Suction Fluid is Water from Shallow Well. Compressed Air parameter is 6CFM Air at 7 bar using 2hp Motor & Compressor set, and required Suction Lift is about 5m. Discharge...

So using the property U†U=1 I was able to get ∑uikujk*=δij where the sum is over k=1,...,n and u is a complex number. from this you get n equations when i=j. If i≠j I get n(n-1) equations but in the notes I'm reading from it...

I was going to try and do an animation of stars orbiting Sagittarius A* but can't seem to find any useful data for it. The Wikipedia page has some data https://en.m.wikipedia.org/wiki/Sagittarius_A* and was trying to reconcile this with https://en.m.wikipedia.org/wiki/Orbital_elements since I...

Hello All, I only have a vary basic understanding of physical concepts so please bear with me. I'm an object with mass greater than 0, a maximum speed, a maximum rate of acceleration and deceleration. Suppose I want to travel from point A to point B. The path is chosen for me and it leads...

i was trying to get a particular solution of a 3rd order ODE using the variation of parameters method the homogeneous solution is yh = c1 e-x + c2 ex + c3 e2x the particular solution is yp=y1u1+y2u2+y3u3 as u1=∫ (w1 g(x) /w) dx , u2=∫ (w2 g(x) /w) dx , u3=∫ (w3 g(x) /w) dx w =...

Hi, I'm doing a project on galaxy clustering and in a lot of papers where they list the cosmological parameters they've used, they list σ8 and ns. Can anyone quickly tell me what these parameters are referring to? Thanks

Hi I'm looking to design a 4 bar compound linkage. I know how torque, force, power and angular velocity are transferred on four bar mechanisms. Could someone help me with compound four bar calculations? http://i66.tinypic.com/2jg6z9t.jpg The lower arrow shoes the input torque. I need to design...

Use the variation of parameters method to find a general solution of $x^{2}y''+xy'-9y=48x^{5}$ $m^{2}-9=0$ $(m+3)(m-3)=0$ $m=3,-3$ $y_{h}=c_{1}x^{-3}+c_{2}x^{3}$ $W=6/x$ Don't really know how to do wronskian with latex so i didnt include the steps. But i need help with the rest of this. i...

Homework Statement Homework EquationsThe Attempt at a Solution Stator Line voltage 220 164 112 88 42 Stator Line Current 6.8 5.4 3.9 3.8 3.7 Stator power 470 360 278 244 232 By plotting a suitable graph from these results, determine the total of windage and friction...

How to write a code can determine optimum over relaxation parameters? Also, is there a code for getting to solve matrix with successive over relaxation method?

Hi All, I am struggling with minimization(maximization) problems which needs to be solved graphically but they have unknown parameter in objective function: For example: f = 2x_1 + \lambda x_2(min) for conditions: -x_1 + x_2 \leq 3 x_1 + 2x_2 \leq 12 3x_1 -x_2 \leq 15 x_i \geq 0 More than...

Hi, So we're doing this Lab on Transient reactance of a synch generator and I'm reading Sarma's classic: Electric Machines Steady-state theory and Dynamic performance p. 474-479 But I can't see how to get the actual exponential time constants for the sub-transient and transient reactances? Thanks

This is not only a question strictly about mathematics, but in science or any other quantitative field in which there is an integration - or a summation that is like a discrete integration. [ A ] the parameter that is considered the input variable for the integration/summati - i.e., the x of dx...

Homework Statement y'' + y = tan2x The Attempt at a Solution yh = c1sinx + c2cosx yp = -y1 ∫ (y2r/W) dx + y2 ∫ (y1r/W) dx r = tan2x y1 = sinx y2 = cosx W = 1 I'm using integration by parts, but I've realized that the trig functions repeat (trivial). Is there another way to solve this...

Homework Statement Find the general solution of the following equation: u(t): u' = u/t + 2t Homework Equations y' + p(x)y = Q(x)....(1) yeI = ∫ dx eIQ(x) + constant.....(2) The Attempt at a Solution I rearranged the equation to give: u' - u/t = 2t Then I considered the following...

Given a ODE like this: y''(t) - (a + b) y'(t) + (a b) y(t) = x(t) The general solution is: y(t) = A exp(a t) + B exp(b t) + u(t) exp(a t) + v(t) exp(b t) So, for determine u(t) and v(t), is used the method of variation of parameters: \begin{bmatrix} u'(t)\\ v'(t)\\ \end{bmatrix} =...

In the EveryCircuit, the element diode has all these parameters: And I don't know what each parameters means... The program don't inform anything, so, what these parameters means? I searched for a manual in the google and don't exist too... And now? Exist so much elements whose with so much...

Hi, 1. Homework Statement C : ℝ→ℝ3 given by C(t)= ( 1/2 [ (1+k)/(1-k) cos((1-k)t) - (1-k)/(1+k) cos((1+k)t) ] ; 1/2 [ (1+k)/(1-k) sin((1-k)t) - (1-k)/(1+k) sin((1+k)t) ] ) with 0<|k|<1 Show that C(t) is an epitrocoid and find R, r and d according to k Homework Equations Parametrization of...

I am not sure that I understand the following: http://www.cplusplus.com/doc/tutorial/pointers/ Why would someone pass an input to a function that he/she doesn't want to modify? And suppose that I want to do that, for example a function that runs a loop over N events determined within the main...

A man with one watch knows what time it is. A man with two watches is never sure. I've seen several combinations of 'standard' λCDM parameters. The NED search site has the three year WMAP as the default and you can select the 5 year as an option. I've seen several papers on the Plank study...

This question is mostly about group theory but I would like to understand it in the context of qubits rotating in a Bloch Sphere. What my understanding of things are right now: In the rotation Lie Group ##SO(3)##, we have three free parameters (##\frac{n(n-1)}{2}##), and this is also why we end...

Hello, I have data for optimization that contains different values of 4 different parameters, and the respective function value based on them. I want to find the maximum of this function, while making sure it's a "stable" maximum, i.e., for nearby parameters, the value of the function shouldn't...

Given a generic second order ODE, normalized that equals to g(x) I saw in a video that, when writing the Wronskian, W1 and W2, for writing W1 you had to "delete" the first column if the Determinant and replace it with zeroes until you reach the end, where you replace it with g(x) Is this always...

I was wondering if anyone has any knowledge of any work that has been done, to use machine learning methods to try to learn parameters good for a physics simulation. Or if anyone has any insight about how this can be done.

Hello I want to know it we have common Emitter s parameters how can we extract s parameters of common base configuration?if there is no problem give me some examples in converting Thank you

Hello everybody, Sorry to ask you something that may be easy for you but I'm stuck. For example I have 2 images (size 2056x2056). One image of reference and the other is the same rotated from -90degrees. Using a program with keypoints, it gives me a transform matrix : a=2.056884522e+03...

Hallo math helpers , i am trying to understand how one could solve the following integrall: $$\int_a^b \mathcal{N}(f(x_1,...,x_n,t),g(x_1,...,x_n,t)) dt$$, where $$\mathcal{N}$$ is the normal distribution, and $$f(x_1,...,x_n,t): \mathbb{R}^{n+1} \rightarrow \mathbb{R}$$, $$g(x_1,...,x_n,t)...

Homework Statement In a course I am studying, I have been asked to calculate the distributed parameters of a line whose Pi model has been provided. I simply quote the question here for clarity of my question: Homework Equations C = \frac{{2\pi \varepsilon }}{{\ln \frac{b}{a}}} R =...

Hi, I am asked to determine the Line Regulation and Load Regulation based on the attached datasheet, using the test circuit parameters listed there. Homework Statement Homework EquationsThe Attempt at a Solution Line Regulation is defined as ΔVo/ΔVI whereas Load Regulation is defined thus...

Can someone verify that my answer is correct ? Thanks in advance. Use Variation of Parameters to find a particular solution to $y'' - y = e^t$ Solution: $y_p = \frac{1}{2}te^t - \frac{1}{4} e^t$

Hi. There is one thing I don't understand: Why do stoke's parameters and all the Jones calculus business apply only to incoherent light? I don't understand how it can work on incoherent light, while fail to work on e.g. monochromatic light. Or am I just confused? All answers appreciated.

Hey, PF: If I have a function ##f(x)## where ##x## is itself a function of another variable (say time), is the following then true? $$f(x)=f(x(t))=f(t)$$ I ask this because if I have the following system of differential equations $$\frac{dA}{dt}=-Bb$$ $$\frac{dB}{dt}=-Aa$$ where litte ##a##...

Homework Statement I am given a four bar mechanism and the mathematical representation of a point on the coupler I am looking for ways to determine the lengths of the linkages from this information? Homework EquationsThe Attempt at a Solution I really have no idea

Just curious, are S parameters related to S-domain and Laplace transforms, or is the use of S just a coincidence? I know that when using S parameters you are working in the frequency domain, but it doesn't seem that you need to use the Laplace transform to use the S parameter concept.

Homework Statement Eliminate the parameter and identify the graph of the pair of parametric equations. Determine the domain (the set of x-coordinates) and the range (the set of y-coordinates). x = sin t, y = -3 sin t - 5 Homework Equations y = -3x - 5 Domain: (-∞,∞) Range: (-∞,∞) The Attempt...

Homework Statement A locked rotor test is performed on a permanent magnet DC machine with the following results: Terminal Voltage 5 V DC Input Current 10 A DC Locked rotor torque. 20 Nm a) Making suitable approximations deduce the effective rotor resistance in ohms? b) Making suitable...

I've been reviewing my knowledge on the technique of variation of parameters to solve differential equations and have a couple of queries that I'd like to clear up (particularly for 2nd order inhomogeneous ODEs), if possible. The first is that, given the complementary solution...

I was thinking about the various complementary parameters in quantum physics. I'm curious if anyone is aware of a "complete" list of such measurements or qualities that has been compiled in one source, based on current knowledge.

Dear everyone, For example, the simplest action for a nonminimally coupled scalar field is S=\int d^{4}x\sqrt{-g}\left[ \frac{1}{2}g^{\mu \nu }\partial _{\mu }\phi \partial _{\nu }\phi -V(\phi )+\frac{\xi }{2}R\phi ^{2}\right]. \xi=0 leads to the scalar field minimally coupled to the...

How much and what type of parameters needs and enough to completely describe moving? Of particle for example.

Can someone direct me to a way to calculate Right Ascension, Declination, Ecliptic Longitude and Latitude of the Sun and Moon from the Julian Date with the accuracy of VSOP87?

Homework Statement Hi guys, so the problem is as follows: A set of n independent measurements y_{i}, i=1...n are treated as Gaussian, each with standard deviations \sigma_{i}. Each measurement corresponds to a value of a control variable x_{i}. The expectation value of y is given by...

Hi, I was wondering if it would be possible for someone to help me clarify a few things regarding transmission lines and transformers? For a Power Transmission line, what exactly is the mutual coupling between phases of a 3 phase line? Is this the same as the shunt capacitance and if not...

I have a problem with some question I had to answer for the Surface Brightness \Sigma \propto \frac{Flux}{Angular~area}= \frac{F}{\Omega}. I was able to show that \Sigma \propto (1+z)^{-4} Then the question asks whether knowing its value for known candles or yardsticks, is a good way to...

There is a quantity (W) that I would like to calculate that is, ultimately, a function of parameters that I can measure directly (a and b), W = W(a, b) But I cannot measure a and b perfectly, there will be some uncertainty in these measurements. This uncertainty will propagate into my...

I previously used the Ziegler method to tune the parameters of my PID controller to control my robot's position. I then implemented fuzzy logic for self-tuning the parameters. I have two inputs to the fuzzy logic controller; one is the position error and the error rate. I know that my problem...