# integral

1. ### QED “All-Path integral approach” for Mirror Reflection

Hi folks! For mirror reflection I have been puzzled by QED “All-Path integral approach” argument. I appreciate if you examine my article and let me know where I have made my mistakes that my reasoning rejects this QED argument. Let us make an observation; if we turn off the pumps of a fish...
2. ### Integral coefficient for internal energy of ionic liquid

I have a question, and I will be really grateful if someone helps me. I have a polynomial equation for internal energy which I calculated by integration an equation of state formula, which is based on density. But, because I calculated this using integration one integration constant which is...
3. ### Dirac Delta function integral

Please see the attachments for details. This is for problem number 1 in homework1.pdf. Basically there is an integral with an absolute value. We are supposed to break the integral into positive and negative parts, integrate, recombine the parts and simplify. Then show that the result...
4. ### Quite Noob Question about IBP

Hi I integral from 0 to inf of : x*e^(-x) dx I use IBP: u = x, du = dx dv = e^(-x) dx, v = -e^(-x) uv - Int v du = -x*e^(-x) - Int -e^(-x) dx I am trying to evaluate the uv term : -x*e^(-x) from 0 to inf for the inf term of -x*e^(-x) = -inf * 1/e^(inf) = -inf * 1/inf = 1 OR -inf * 1/e^(inf)...
5. ### Feynman Path Integral - Particle Through Space

Hey guys :) I have 3 simple questions regarding Feynman Path Integrals: 1. Are Feynman Path Integrals simply another type of integral, with more steps required to calculate them? For example, is the difference between a regular path integral and a Feynman path integral analogous to a...

This is a new question, I am just using the old thread because the tittle applys. I want to find the vector potential A at origin due to a current segment I(t)=kt flowing along x axis from -b<x<-a where b>a. This mean from -b to -a on the left of the origin. I did not write...
7. ### Acceleration, Velocity, and Position (Integral Calculus)

Note: For some reason, I am receiving a "Can't write to directory error" when I try to use LaTeX. One of the problems in my Physics textbook demands a proof of the following equation: ( v^2 - (v_0)^2 ) / 2 = integral a(s) ds from s_0 to s. The right-hand side of the equation evaluates to v(s)...
8. ### HELP! Stuck on a surface integral..

i'm stuck on a surface integral. help, please!! z = f(x,y) = 9 -x^2 over the region R: square with vertices (0,0), (3,0), (0,3), (3,3).
9. ### Need help with Proper integral of a uniformly charged rod

A uniformly charged rod is places along the x-axis from x=0 to x= L. carefully set up, but do not solve the proper integral to determine the x component of the electric field at the point (L,a) i know for a line dq=λdl i think its something along the lines of Ey=Kλy= \int...
10. ### functional integral method in condensed matter physics

is there anyone who is familiar with functional integral method in condensed matter physics?i have a problem when using it to deal with the superconductivity.could you please contact me through my email [email protected]
11. ### need help to evaluate this integral

integral from lim 0 to infinity { [1/ (p^2+a^2) ] * e (-ibp) }dp where i=(-1)^.5 a,b=const. p= momentum if anyone have mathematica plz.help me calc it.atleast tell how to proceed with the integral.does it fall under any std. integral.form. can any of you suggest any book or site from...
12. ### integral physics application problems

integral physics application problems We are now applying calculus to physics problems and I am having trouble coming up with the correct integrals. An anchor weighing 100 lb in water is attached to a chain weighing 3 lb per foot in water. Find the work done to haul the anchor and chain...