Midterm 2011 Solutions

6 ev for hydrogen maxwellboltzmann distribution nv is

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ation (AU) / distance (pc) For radians, separation and distance must be in same units Parallax: π(“) = 1/d(pc) Tangential speed: Vtan (km/s) = 4.74 µ (“/yr) d(pc) µ is the magnitude of proper motion Doppler shift: λ0 is the rest frame wavelength, Vrad is the radial motion, positive for motion away from observer ∆λ = λ 0 Stefan ­Boltzmann Law: F = σ T 4 L = 4π R2 σ T 4 F is the flux, T the temperature, L the luminosity and R the radius Blackbody distribution: B(T) is a spectral radiance: energy per unit time per unit area per unit wavelength per unit angular area Wein’s Displacement Law: Vrad c Bλ (T ) = 2hc2 1 5 ehc/λkT − 1 λ λpeak is the peak wavelength of the blackbody distribution λpeakT = 2898 µm K Potential energy for e ­ orbital state n in a Hydrogen ­like atom: En = −χi /n2 Degeneracy for orbital state n: gn = 2n2 χi = 13.6 eV for Hydrogen Maxwell ­Boltzmann Distribution: n(v) is the number density of particles with velocity v, n is the total number density, m is the particle mass n(v )dv = n Ideal gas pressure law: n and ρ are the number and mass densities, m = µmH is the individual mass M ≈ uNnucleon is the molar mass P = nkT = Page 18 of 19 m 2π kT 3/2 e−mv ρRT ρkT = µmH M 2 /2kT 4π v 2 dv Physics 160 Fall 2011 Radiation Pressure Law Mean molecular weight: Aj = mj/mH, Nj is the number density and zj is the proton number of species j P= Boltzmann equation: Ni is the number of atoms in a given orbital state i Midterm Exam 14 aT 3 j µn = Nj Aj j Nj for neutrals Nj Aj j 1+zj µi = j Nj for ionized gas Ni gi = e−(Ei −Ej )/kT Nj gj ∞ Partition function: gi e−(Ei −E1 )/kT Z1 (T ) = i=1 Saha equation: Nm...
View Full Document

This document was uploaded on 02/26/2014 for the course PHYS 160 at UCSD.

Ask a homework question - tutors are online