A river delta is a landform created by deposition of sediment that is carried by a river as the flow leaves its mouth and enters slower-moving or stagnant water. This occurs where a river enters an ocean, sea, estuary, lake, reservoir, or (more rarely) another river that cannot carry away the supplied sediment. The size and shape of a delta is controlled by the balance between watershed processes that supply sediment, and receiving basin processes that redistribute, sequester, and export that sediment. The size, geometry, and location of the receiving basin also plays an important role in delta evolution. River deltas are important in human civilization, as they are major agricultural production centers and population centers. They can provide coastline defense and can impact drinking water supply. They are also ecologically important, with different species' assemblages depending on their landscape position.
1.>Consider a gas in a vessel with a piston on top.Let it expand to a greater volume.
So,
delta H=delta U+delta(PV)
but delta U is 0 as it is isothermal.
now,as the number of moles of gas remains constant,delta(PV) is nR(delta T) which is again 0.
SO delta H is 0.
Thats what my book says...
Hello Again!
My question:
Find the bound energy spectrum of the potential that contains two delta-function
wells: V(x) = -V_{0}\delta(x-\frac{a}{2}) -V_{0}\delta(x+\frac{a}{2}) under the assumption that the wells are located very far away from each other. Find and plot the associated stationary...
I have a question about delta functions. What I want to believe is the following
\int_{-\infty}^{0} \, dt \, f(t) \delta(t) = \frac{1}{2} f(0).
It even shows up on Wikipedia (so it must be true!)
Here is an argument (I know it isn't a proof). If I use the "delta-sequence" approach and...
Anyone know where I can find a discourse on the dirac delta function in spherical or polar coordinates, in particular why it is the form it is with correction coefficients?
Thank you.
Homework Statement
Dear all,
I have a problem when I using MATLAB to get the Fourier transform of dirac delta function. below is my code.Homework Equations
clear all;
clc;
close all;
% t=0:0.002:2;
t=0:0.002:4;
dt=t(2)-t(1);
u=zeros(size(t));
pos0=find(t>=1,1);
u(pos0)=1/dt...
Homework Statement
Find delta f of f=Z^-1 * Sqrt(9x^2*y^2)
at point (1,4,10)
Homework Equations
f =f+(fx*delta x )+(fydelta y)+(fz*delta z)
The Attempt at a Solution
fx = 9*2x/(z*(2*sqrt(9x^2*y^2)) =.18 plugging in (1,4,10)
fy=2y/(z*(2*sqrt(9x^2*y^2)) =.08
fz=(sqrt(9x^2*y^2) )...
hi guys
i want to find
i took the integral of δ(τ+2) and I said that it's basically u(t+2)
δ(τ-2) is u(t-2)
so we have u(t+2) - u(t-2) = 2 from -2 to 2..
well after that i need to get the absolute value of this and then the power of two, i don't know how to do this..
my book...
In a given distance apparently regardless of how much work is done (whether the force is large or small) the change in thermal energy is the same since thermal energy change is fk times d. Since Fk is constant as is D the change in thermal energy of the system will remain constant. I'm having...
Homework Statement
find an open interval about x0 on which the inequality lf(x)-Ll<\epsilon holds. Then give a value for \delta>0 such that for all x satisfying 0<lx-xol<\delta the inequality lf(x)-Ll<\epsilon holds
f(x)=x2
L=3
x0=-2
\epsilon=0.5
Homework Equations
The Attempt...
i don't really understand the dirac delta function in 3D.
is it right that integral of f(r)d3(r-a)dt = f(a)
where a = constant ,r is like variable x in 1D dirac delta function?
so why when i have f(r')d3(r-r') , it picks out f(r)?
where r is now a constant and r' is a...
Recently in adv calc we have been dealing with the epsilon delta definition for continuity, and my professor said that it is ok to assume that delta<1. I actually used this to show that x^4 satisfies the epsilon delta condition but I'm not quite sure why we can take delta<1. I am sure you guys...
[PLAIN]http://img820.imageshack.us/img820/5817/img8968h.jpg
Any hints please, just starting question. Haven't really done any questions like this before
Hello all,
I joined this amazing forum just today.I hope that my question will get answered soon.
So here it is.I am unable to understand a some steps in calculation. Please help me understand.
Here is a linear homogeneous first order differential equation
whose solution a research...
Homework Statement
Let \vec{A}(\vec{r})and \vec{B}(\vec{r}) be vector fields. Show that
Homework Equations
\vec{\nabla}\bullet(\vec{A}\vec{B})=(\vec{A}\bullet\vec{\nabla})\vec{B}+\vec{B}(\vec{\nabla}\bullet\vec{A})
This is EXACTLY how it is written in Ch 3 Problem 2 of Schwinger...
Although I am an aspiring physicist, I cannot cope with the physicist's love for vagueness when it comes to yielding math. Exactness is simply not a luxury that can be ignored, certainly not in theoretical physics.
But okay, I realize the dirac delta function can be made exact by the use of...
I am confused from a couple of diagrams I have about how to correctly wire 3 small transformers to form a delta wye connection. The transformers are labeled as
Primary H1 H2, H1 H2, H1 H2
Secondary X2 X1, X2 X1, X2 X1
My question is in all the diagrams I have the Delta connections...
So I've been told that the Dirac delta functional is a distribution, but I don't see why that's the case. I had an introduction to distributions in my calculus IV course, but as I remember it, a distribution involves and integral containing a the product of a function from the Schwartz space and...
i need help trying to find the laplace transform of te-t\delta(t)
i know the laplace transform of te-t is 1/(s+1)2 but i don't know how to find the laplace transform of a product with the Dirac delta
Hi this is my first post here so I'm sorry if my question seems trivial.
I haven't worked a lot with the dirac delta function before, so i always thought that the shifting property would only work as:
\int\delta(x-h)\;f(x)\;dx=f(h)
Now I've been reading some articles and I came across...
I understand that the Dirac delta function can be taken as a distribution. And that one can calculate the Shannon entropy or information content of any distribution. So what is the information content of the Dirac delta function? I think it is probably identically zero, but I'd like to see the...
I'm designing a new spacecraft model, but it does not use Delta wings, like most ships do. I need them to be efficient, because my ship is kinda large. (It's like a hybrid of a rocket, and the Space Shuttle), and so I have two questions:
1) My craft's wings look like really tall right...
Hi folks, I am new to physics forums , an engineer by profession, I have newly developed some interest for pure physics, can someone please enlighten me on the violation of energy conservation by the time energy UP? The way I understand it the principle only puts a LOWER bound.
Is...
I have a problem on a take-home test, so I can't ask about the specific problem. So this is just going to be a general, how do I put stuff together problem.
I have a function of x and y that maps R2 into R1. The limit as (x,y)->(0,0) is zero, and I've worked through the various paths already...
Homework Statement
Define: f(z) \rightarrow w1 as z \rightarrow z0
and
g(z) \rightarrow w2 as z \rightarrow z0
prove that f(z)/g(z) \rightarrow w1/w2 as z\rightarrow z0
The Attempt at a Solution
let \epsilon > 0
choose \delta > 0 such that:
|f(z) - w1| < ______...
Homework Statement
Is my understanding correct?
As delta(y) and delta(x) approach X from points to the left and points to the right of X (x is what we wish to find the derivative of) then the x and y values of points to the left and right approach the x and y values of X.
And as the...
hi, i don't understand why levi civita symbols is equal to kronecker delta when i was reading the wikipedia on it http://en.wikipedia.org/wiki/Levi-Civita_symbol
namely,
1)why does EijkElmn = det [ 9 terms of kronecker delta]
how do we know its those 9 terms? like dil dim din etc
2)and since...
Homework Statement
a) A charge q1 = q is at r'1 = -Di, and a charge q2 = -3q is at r'2 = Di. Find an expression for the volume charge density p(r).
b) An infinitely long wire along the z-axis has a uniform linear charge density \lambda. Find an expression for the volume charge density p(r) in...
Homework Statement
prove that the lim as x goes to 4 of x^2 + x -11 = 9
This is the example used on Paul's Online Notes on limits in calculus which can be found here http://tutorial.math.lamar.edu/Classes/CalcI/DefnOfLimit.aspx (I really like this resource.)
Homework Equations
Paul...
Is this legal? I assumed that delta x is a constant that is approaching zero. So I brought it out. When I took the derivative, the delta x canceled out with the denominator. So I'm left with the derivative of the intergral of f(x) with respect to itself. So I'm essentially trying to find the...
Hi,
I am looking for approximations to the delta functoin which I can use on a computer. Although I will never get an exact delta function, I can make an approximation that it can be improved as much as I like.
Would you help me to find the approximation of the delta function so that I can...
Homework Statement
a.)
Given \delta_n=\frac{ne^{-{n^2}{x^2}}}{\pi}
Show: x{\frac{d}{dt}\delta_n}=-\delta_n
b.)
For the finite interval (\pi,-\pi) expand the dirac delta function \delta(x-t) in sines and cosines, sinnx, cosnx, n=1,2,3... They are not orthogonal, they are normalized to...
Hopefully people are still prowling the forums this close to christmas :)
I want to show that sin(ax)/x is a representation of a delta function in the limit a->infinty i.e
1) It equals 0 unless x=0
2) integrated from plus minus infinity it equals 1 and
3) multiplying by an arbitrary...
The Solubility Constant for AgI(s) at 25 degrees Celsius is 8.3*10^-17
how do i find \DeltaG(rxn) for [Ag+]=9.1*10^-9 & [I-]=9.1*10^-9
Using the equation:
ΔG=ΔGº+RTln(Q)
Let K=Our solubility constant:
0=ΔGº+RTlnK
ΔGº=-RTlnK
Now,
ΔG=-RTlnK+RTlnQ
ΔG=RTlnQ-RTlnK
ΔG=RT(ln(Q/K))
ΔG=-5.67KJ/mol...
does the epsilon delta definition of the limit connect to the uncertainty in measurements like this? like if we measure a quantity time with value a with error of + or - delta then my formula will give me v with value L +or - epsilon or is it unrelated?
NOT A HOME WORK QUESTION
how do i know if a delta potential function is given if its solution is even or odd? do i look for symettry or something
take this function for example:
V(x)= -alpha[delta(x+a) + delta(xa)]
i skeched the following graph.
since V(-a)=V(a)...
Homework Statement
Sodium metal reacts with water to produce hydrogen gas and sodium hydroxide
according to the equation:
2 Na(s) + 2 H2O(l) ? 2 NaOH(aq) + H2(g)
When 0.030 mol of Na is added to water, the temperature of the calorimeter rises
from 25.00C to 37.90C. If the heat...
Homework Statement
Let's say we have a wire of finite length L with total charge Q evenly spread along the wire so that lambda=Q/L, linear charge density, is constant. The wire is shaped in x-y plane in some well behaved curve y = f(x). Find the surface charge density sigma(x,y).
Homework...
Homework Statement
Prove using the Levi-Civita Tensor/Kroenecker Delta that:
(AxB)x(CxD) = (A.BxD).C-(A.BxC).D
Homework Equations
εіјkεimn = δjmδkn – δjnδkm (where δij = +1 when i = j and 0 when i ≠ j)
The Attempt at a Solution
if E = (AxB) then Ei = εіјkAjBk, and
if F =...
I am looking at a problem, part of which deals with expressing delta dirac as a limiting case of gaussian function. I am aware of the standard ways of doing it. In addition, I would also like to know if the following are correct -
\delta(x-a) = \lim_{\sigma \rightarrow{0}} \int_{a -...
i need to prove that for every delta
i call d=delta
e=epsilon
1/|x+1|>e
we can choosr any e we want
so they took e=1/4
but because the innqualitty needs to work for every delta
they took x=min{2,(1+d)/2}
for d>2 it takes x= 1+d /2
for d<2 takes x=2
uppon what logic they found this...
Homework Statement
I have infinite square well which has a potential V(x)=\frac{\hbar^2}{m}\Omega\delta(x) in x=0, and is 0 in the interval x\in[-a,a]Homework Equations
Schrodinger eq.The Attempt at a Solution
I solved the time independant Schrodinger eq. by integration around x=0 by some...
So my physics book says "from x(final)=x(initial)+V(initial)t+1/2at^2 observe that when x(final)=x(initial), the time is given by t=-2V(initial)/a"
Now if change in x is equal to 0, wouldn't your velocity v(initial)t from above along with your acceleration also be zero?
How is the book getting...
This isn't a HW question just something I am curious about. I was looking on wikipedia and found a way to prive the Levi-Citiva Kronecker Delta relation that I hadn't seen before.
The site claims
\epsilon_{ijk}\epsilon_{lmn} = \det \begin{bmatrix}
\delta_{il} \delta_{im} \delta_{in}\\...
\Delta H_{f}\circ=-1670kJ/mol for Al_{2}O_{3}
What is \Delta H_{rxn}\circ for
2Al_{2}O_{3}(s)\rightarrow4Al+3O_{2}(g)
So clearly we simply multiply -1670*2=-3340kJ/mol.
The answer is actually POSITIVE 3340kJ/mol!
Can someone please explain to me how this reasoning works?
Thank you!
Hello all. So I am trying to integrate a function of this form:
\int\intF(x,y)\delta[a(Cos[x]-1)+b(Cos[y]+1)]dxdy
The limits of integration for x and y are both [0,2Pi). I know that this integral is only nonzero for x=0, y=Pi. So this should really only sample one point of F(x,y)...
Homework Statement
I am new to FT and dirac delta function. Given the following signal:
x\left(t\right)=cos\left(2\pi5t\right)+cos\left(2\pi10t\right)+cos\left(2\pi20t\right)+cos\left(2\pi50t\right)
I use the online calculator to find me the FT of the signal, which is...
Homework Statement
\int_{0}^{b} \int_{0}^{2\pi} C_{k,m}(r)^2 \left{\begin{array}{cc}cos(m\theta)^2\\sin(m\theta)^2 \end{array}\right} r dr d\theta
Homework Equations
See above
The Attempt at a Solution
Ignoring the 'r' integral for a second, the solution that I see written...