Homework Statement
A projectile is launched with a speed v at an angle theta above the horizontal. Ignore air resistance. Derive an expression for the angle theta in terms of the parameters of the problem such that the horizontal distance from the launch of the object is N times greater than...
Homework Statement
Find the h parameters of the following systems:-
---L---------C--
:
:
R
:
:
----------------
L= j5 ohm
C=-j5 ohm
R=1 ohm
Homework Equations
The above questions has to be solved manually as well as simulated...
Homework Statement
The electric field of an electromagnetic wave is given by;
E = Re(\frac{1}{\sqrt{13}}E_{0}(2\widehat{x}+ 3i\widehat{y})e^{i(kz-wt)})
Identify the polarization state.
Homework Equations
I = |E_{x}|^{2} + |E_{y}|^{2}
Q = |E_{x}|^{2} - |E_{y}|^{2}
U = |E_{a}|^{2} -...
Homework Statement
Measurements of the height h(t) of water in a harbor are recorded ,where h is measured in meters and t in hours.It was noted that the rise and fall of a tide is modeled by a sinusoidal function giving the height by : h(t)=a+bsin(kt+c).
(a) Obtain values of the...
Exponential function with 3 parameters??
Homework Statement
A researcher suggests that the population, P, at time t can be modeled by
P(t) = K / (1 + Le^(-Mt)), where K, L and M are parameters.
Use technology to estimate and interpret K, L,and M. Construct the researcher's model using...
Homework Statement
I have a frequency equation to solve for the displacement for a spring mass damper truss system, as seen below,
[m]u''+[c]u'+[k]u=f(t),
where m,c,k, are all matrices (2x2), and f(t) is a graph-defined forcing function. I am to use 3 nodes, using the central...
Homework Statement
We have that for a crystal the lattice parameters (in angstrom and degree) are:
a b c (in Angstrom)
10.5 10.5 10.5
\alpha β γ (in degree)
109.5 109.5 109.5...
Hi all,
I would like some help understand the covariance and correlation matrix as it pertains to estimated parameters. I am performing logistic regression with just one independent variable and a constant term.
I am wondering if someone can help me understand the information these...
hello :)
let's look at the following functions:
Langevin function L(x)=ctgh(x)-1/x
Brillouin function B(x)=f(x J); when J→∞, then B(x)=L(x)
to which I have the following questions:
- how was the Brillouin function B(x)=f(x,J) developed?
- are there other functions with the...
Hi,
I've got a question about fitting a known function to a measured data.
Suppose I want to find X parameters by fitting a curve to some measurments - What is the minimum number of measurements needed?
Someone has told me that I need X+1 measurments, (because one degree of freedom), but...
i am buying Pulsed Laser Diode in Plastic Package 25 W Peak Power SPL PL90 and there is some parameters about semiconductors lasers...
Forward current = 40 A why all this current ?
then in the catalog Reverse voltage= 3 Volt
then they say the Threshold current = 1A ? what is the...
In Euclidean three-space with coordinates (x,y,z) and line element
ds^2 = dx^2+dy^2-dz^2
It is easy to show using the geodesic equation that:
x = lu+l', y=mu+m', z=nu+n'
where u is an affine parameter.
However, is it possible to find a relation between l,m,n?
Homework Statement
Solve using variation of parameters
y''' - 2y'' - y' + 2y = exp(4t)
Homework Equations
Solve using variation of parameters
The Attempt at a Solution
I got the homogenous solutions to be 1, -1, and 2.
So, y = Aexp(t) + Bexp(-t) + Cexp(2t) + g(t)
I got...
The question I'm trying to solve is:
y" - 6y' + 9y = \frac{exp(3x)}{(1+x)}
I formulated the Gen solution which are:
y1(x) = exp(3x) and y2(x) = xexp(3x)
I've then calculated the wronskian to get: exp(6x)
I then went onto to use the variation of parameters formula, which is where...
I am solving for the Y and Z parameters for the circuit below:
For Y, I used the following equations by applying current sources at the terminals
va is the node at the 2v1 dependent source
(va-v1)/0.5 + (va-v2)/1 = -2v1
I1 = v1/1 + (v1-va)/0.5
I2 = v2/0.5 + (v2-va)/1
I got Y = [3 -2/3; 0 8/3]...
I just realized you can use variation of parameters (VOP) to solve for homogeneous 2nd order equations. I see it takes much longer to do so. But I was wondering why, if you use VOP, the u and v functions are 0. Is this because the coefficients of the homogeneous equation are constant, or...
Find the complementary solution of y^\left(4\right) + 2y'' + y = sint
Homogeneous Form would be y^\left(4\right) + 2y'' + y = 0
r^4 + 2r^2 + r = 0 \rightarrow r(r^3 + 2r + 1) = 0
This is where I'm stuck. Once I find y_c(t) I should be able to finish the problem, but I'm having trouble at this...
Hello. I have three questions that I would like to ask.1. Could someone provide me with a resource containing examples of arbitrary parameters in theoretical physics. E.g. a modern example, yet to be varified, is dark energy. A historical example, one which has since been discredited, is the...
for the following circuit, i am trying to find the y parameters
i have found y11, y12, and y22 to match the answer that my text provides, but i am having trouble with y21
the solution given is y11 = 1.5, y12 = -0.5, y21 = 4, y22 = -0.5
in trying to solve for y21, i get 4.5
this is...
Homework Statement
I must solve (1-x)y''+xy'-y=(1-x)^2 knowing that y=x is a solution if the right hand side is 0. I must use this fact in order to obtain the general solution to the DE
Homework Equations
Variation of parameters?
The Attempt at a Solution
I'm looking at...
Please teach me this:
Is it possible there are corresponding mass parameters for different types of interaction for a certain particle?.Because each type of interaction has an own contribution in total mass.Then considering quarks with electro-weak interaction,despite nonzero total mass of...
Homework Statement
Measuring the flux of a star as a function of the time, the flux exhibit a decrease of 1.65% for 2h 56m, periodically every 57.22 days. Such decrease is ascribed to a planet transit.
The continuous spectrum of the star is like a black body with T= 9500 K, and its...
I've picked up a bit more since my last problem. I need to solve the following DE:
x^{2}\frac{dy}{dx}+x(x+2)y=e^{x}
I decided to use variation of parameters, so I re-arranged it like so:
\frac{dy}{dx}=\frac{e^{x}}{x^{2}}-(1+\frac{2}{x})y
Then solved the homogenous DE...
Right now, my Achilles heel is a pokey DSL connection, but still, there is some software that I like to use that load quite slowly on my old PC. I have a Dell Dimension 8400 that must be 7-8 years old now, and I've been thinking about passing this one on to my neighbors' grand-daughters. They...
I need to find a solution to the following problem:
(x^{2}-1)\frac{dy}{dx}+2y=(x+1)^{2}
y(0)=0
I decided to try using variation of parameters. My teacher was unable to show any examples, and I'm having issues understanding the textbook.
From what I see I need to get it onto this form...
I'm doing my economics thesis on game theory, and need to solve a system of nonlinear equations (these will be the reaction functions). Unfortunately, I have no idea how to solve it explicitly--indeed, I am a bit worried its impossible with the parameters. It is rather symmetric though.
The...
Homework Statement
Using the variation of parameters method, find the general solution of
x^{2}y" - 4xy' + 6y= x^{4}sin(x)
Homework Equations
y_{P}=v_{1}(x)y_{1}(x) + v_{2}(x)y_{2}(x)
v_{1}(x)'y_{1}(x) + v_{2}'(x)y_{2}(x)=0
v_{1}(x)'y_{1}(x)' + v_{2}'(x)y_{2}(x)'=x^{4}sin(x)...
Homework Statement
Find a particular solution for these second order differential equations.
Homework Equations
1) y''+9y=tan3t
2) y''+y=tan^2t
The Attempt at a Solution
I want to find a fundamental solutions y1 and y2 because I want to find a particular solution like this...
Homework Statement
Solve for general solution with variation of parameter
y'''(x) - y'(x) = x
The Attempt at a Solution
I initially looked at y'''(x) - y'(x) = x only and I foudn my answer to be
y(x) = C_1e^{x} + C_2e^{-x} + 1 - x
Now i looked through my book and it says it works for...
Hi all,
I have a question regarding least-squares, and I'm certain I can't be the first one to encounter it, but I've had no luck searching the literature for a solution. Here it is:
Say we have a non-linear least-squares optimisation problem. We have data points y_i and a model y(x_i;{\bf...
Hi guys,
i can't seem to find the answer .
A satellite in Earth orbit has a perigee velocity of 8 km=s and period of 2 hours. From this information,
determine all the orbit parameters that you can. From those parameters, determine its altitude at perigee...
Does anyone know any sources (i.e. car manufacturers) that provide the exhaust air flow parameters for the some specific car engines? I need stats on various otto & diesel cycle engines (small compact car engines, large semi truck engines, etc.). When I say exhaust air flow parameters, I need to...
Homework Statement
Several velocities, time, and length scales are useful in understanding what goes on inside engines. Make estimates of the following quantities for a 1.6-liter displacement four-cylinder spark-ignition engine, operating at wide-open throttle at 2500 rev/min.
a. The mean...
Homework Statement
The brake fuel conversion efficiency of an egine is 0.3. The mechanical efficiency is 0.8. The combustion efficiency is 0.94. The heat losses to the coolant and oil are 60 kW. The fuel chemical energy entering the engine per unit time, (m_f * Q_HV), is 190 kW. What...
Given t^2 y'' -t(t+2)y' = (t+2)y= 2t^3 and y1= t, y2= te^t
Find the particular solution-
I ve worked the problem to [ -2t^2 -2t] by:
-t * Integral [ 2t* te^t/ t^2e^t] + te^t * Integral [ 2t^2/ t^2e^t]
whereas the book states that it is simply -2t^2. Can you guys tell me where I made...
Murnaghan equation for lattice parameters?
Hi everybody...
I'm trying to determine lattice constant (a) for BN by calculating the total energy for different values of a using ABINIT, then chose the one which correspond the minimum value of energy, Is this convenient way to determine a ...
Question basically asks to find the parameters of a transformer via an open circuit and closed circuit test. We were taught that for OCT,
V = (I * cos(theta)) * R
V = (I * sin(theta)) * X
To find the core losses. This makes sense, since we are only using the component of the current that...
Homework Statement
In feedback problems of amplifiers we often use H feedback in the voltage controlled voltage sources... The good thing about that is that they are connected in series parallel form and they are then to find the net h parameters we simply add the h parameters of the...
E/M waves can be polarized, presumably, by filtering either their electric or magnetic transverse vectors.
What about matter waves? Can they be electrically or magnetically polarized? Can they be polarized with respect to spin, parity, or any other parameter?
That's a lot of...
Hi there! I'm working on analyzing some data from an experiment, and you can see a graph of some of the results in the attached .jpg image. I've done both a linear and a quadratic fit on the data points, weighted to error bars (the red lines are the fits). I use percents in the graph, but I'd...
Homework Statement
\mathbb{x'}= \begin{bmatrix} 1 & 1 \\ 4 & 1 \end{bmatrix} \mathbf{x} \ + \ \begin{bmatrix} 2e^{t} \\ -e^{t} \end{bmatrix}
Find the general solution.
Homework Equations
The Attempt at a Solution
Well i found the eigenvalues of the matrix That i'll call...
For example, mass spectrum can't vary because energy is conserved (locally).
What's about other parameters? Could CKM angles be different in earlier époque? It could save the Sakharov’s mechanism, if CP violation was more intense during bareogenesis.
HI, I want to reproduce results from the article (attached).
I need to get parameters of interaction between atoms of H2 and C6H6 for Morse equation.
I easily got results of interation between MOLECULES H2 and C6H6, shown in Table S2 'The first-principles and Morse force field (eq.1)...'...
Hi there,
first, I apologize for my poor English.
I made a simulation model and get results from HFSS
Model has a equivalent circuit like that.(1)
I run that model and get pair of solutions 'frequency vs response' like S parameter for each frequency.
So, with these results, is it possible to...
Greetings,
Maybe I'm getting a little bit confused, but I'm looking for resources which explain how to update parameters of a Bayesian network as a result of observations.
There are various inference methods, but unless I'm missing something here, these methods produce a posterior...
Homework Statement
These conditions include the following:
(1)radius must be as small as possible.
(2)It needs to be possible to park a car on the curve without sliding off on an icy day when coefficients of static and kinetic friction are .2 and .1 respectively.
(3)Cars need to make the...
Homework Statement
Hi
I'm looking for an algorithm that can perform a fitting procedure on many curves simultaneously. Let's say, for example, that I have 3 exponential decay curves with 3 different decay times but they all share the same initial amplitude. So I have to find a fit for 4...