Recent content by lavenderblue

Thank you! :-)

Homework Statement Estimate the radius of a spherical HII region which rests at a distance of 500 pc that subtends an angle of 20' at the observer. [1'=3x10-4 radians] Homework Equations L=D(theta) Where D is the distance, L is the angular size and theta is the angle. The Attempt...

This question is on the radius of a shell, which is: R[shell] = ((Luminosity*time^3)/(density))^1/5 I have been asked to prove this using dimensional analysis, and have broken the quantities down into their basic units, but seem to be getting really funny answers (with most of the powers...

I'm using the equation: E=gamma*m I want to know what the units of each of the quantities are. If I want to calculate the Lorentz factor, then do I need to make sure that both the Energy and mass have the same units? I am also using the equation for length contraction: L=L0*gamma Do I...

I was told that geometry of the cone is flat with K=0 everywhere except z=0. Do I use the expression for Gaussian curvature for a parabaloid?

I was told this by a GR lecturer. But I'm not sure of the mathematics!

Hi, I know that you can determine that the Gaussian curvature of a cone tends to infinity at the vertex, but seeing as the curvature anywhere else on the cone is zero, how is this possible?

Hey I have been asked to find the first and second derivatives of lx-al-lx+al I have, for the first derivative got, sign(x-a)-sign(x+a) and for the second, i have: 2(delta)(x-a)-2(delta)(x+a) am i right in both cases? I also have to draw them 'schematically' how do i do this?

I need to convert the intensity, 130 counts per pixel into magnitudes per sq arc second. I have been given the radius as 5 arc sec, and a calibration constant, which is 30.8.

I need to show that the spherical harmonic, Y^-1 of l=1 is Normalized. Y(m=-1, l=1) = sqrt(3/(8(pi))sin(theta)exp(-i(thi))

Hey, I've been asked to find the minimum thickness for a slab of crystalline sapphire. The equation for the half wave plate is : d(ne-no) = (m+1/2)*lambda I found the minimum by using the fact that m=0 It then asks what the other wavelengths are which will allow the plate to act as a...

Compton scattering and the energies of incident and scattered photons...? [b]Hey guys! I'm alittle stuck...Hope you can shed light on this for me! The question is: 'In a head-on compton encounter, the total energy (i.e the rest mass plus the kinetic energy) of the scattered electron is...

Help with Quantum please! If a1=a2=a then show that any linear combination (psi)=a1(psi)1 + a2(psi)2, where a1 and a2 re arbitrary complex numbers, is also an eigenstate with th same eigenvalue i.e. show that A(psi)=a(psi) Could you please show your full workings I don't know where to start...

Hey, this is going to be abit long winded... In a Stern-Gerlach experiment a beam of hydrogenic atoms in the l=1 state traveling along the y-axis is first passed through an inhomogeneous magnetic field in the z-direction to yield three beams corresponding to three eigenstates Y(z,1), Y(z,0)...