Recent content by eas123

So where have I gone wrong?

I was wondering how you prove that ∫(e^iax)(e^ibx)dx from minus infinity to infinity is zero. When I try to evaluate this in the usual way, the result is undefined. Thanks in advance for your help!

Hi. :-) What do you mean? I don't know how to derive the expression.

Homework Statement See attached. Homework Equations The Attempt at a Solution I integrated the equation with respect to x to obtain ∫\frac{d}{dx}(xe^{-x}\frac{df}{dx})dx+∫ne^{-x}fdx= constant The first term on the left hand side goes to zero as x, df/dx are bounded at 0...

Hi. For a Bose gas, my textbook states that below the critical temperature, which is given by n(λth)3/(2S+1)=2.612, the fugacity z=eβμ≈1. Why is this? The most basic explanation possible would be ideal, as I only need the rough idea. Thanks! :smile:

This is the point I don't understand. Since dl and B are perpendicular, dl x B = B dl, but that's not a function of theta...

Hi. I'm trying to use the method above but I'm having some problems. dT=rcosθdF, and T=4∫dT between 0 and π/2. But I don't know how to write dF as a function of dθ. How do I use the expression dF=I dl x B to find dF? Thanks so much!

Thanks so much for your help. I'll try the method you suggested now. :thumbup:

Homework Statement A circular coil of radius r carries a current I. A magnetic induction B acts at right angles to a diameter of the coil. Show that the current experiences a torque T about the diameter given by T=Iπr^{2}Bsinω, where ω is the angle between the normal to the plane of the coil...