Recent content by Physics Dad

Hi, thank you for your response. The massive stars do not add up to 105M⊙. They are very rare in a star cluster, it is a case of trying to work out how many of the total stars in the cluster are in this 30 - 150M⊙ category. The Salpeter function Φ(M) has been found to be M-2.35 consistently...

Assumptions: 1) The minimum stellar mass in this cluster is 0.1M⊙ 2) The maximum stellar mass in this cluster is 150⊙ First calculate the local stellar density constant (ξ0) for this cluster using eq 1: Having rearranged this equation and using the limits of the minimum and maximum stellar...

Hi, I am currently studying for a masters in Astrophysics and am in my Stellar Atmospheres module. One of the questions I have been asked is with regards to the shock breakout of supernovae. Basically, the question is which type of stars show the strongest shock breakout and why? My thinking...

Thank you for the reply. It was the log(e) that was confusing me, all sorted now!

Hi, I am working on a Boltzmann equation question and I know that the solution I am looking for is that: log(nij/nji)=log(gij/gji)-Eij(eV)(5040/T) The only thing I don't understand is why log(e-Eij/kt) = θ = 5040/T From what I have read in textbooks, it is just a given, but I really want to...

I have made an effort to answer this question, and would like to know if my thinking is correct. I would appreciate any feedback. Thank you! Homework Statement Two stars in the sky have similar effective temperatures, masses and apparent brightness. However, star 1 has a surface gravity...

I have made an attempt at the question below and just wanted to check if my thinking was correct or totally wrong. Thank you in advance! 1. Homework Statement In a simple model of a star, the density is described as ρ=ρ0(1-r/R), where R is the stellar radius, and ρ0 is the central density...

So Q = p dv = p 4πr^2 Dr Again, for case 1 and 3 this would still be zero. For case 2 this would be integrated from r2 to r1? So Q = 2Aπ(r2^2 - r1^2) So E = A(r2^2 - r1^2)/2€0r^2 Sorry, doing this on my phone, have no symbols. Thanks

Yes, fair enough, I meant equated Qenc in terms of ρ. Is there anything else wrong with my attempt? Many thanks

An insulating spherical shell of inner radius r1 and outer radius r2 is charged so that its volume density is given by: ρ(r) = 0 for 0 ≤ r < r1 p(r) = A/r for r1 ≤ r ≤ r2 p(r) = 0 for r > r2 Where A is a constant and r is the radial distance from the center of the shell. Find the electric...

Hi, I have a very basic statistics homework question, and I have given it a go, but I just wanted to know if I had approached it correctly: QUESTION A shop adjusts its staffing levels using a model of customer demand through the week in the ratio of: 0.22(Mon); 0.14(Tue); 0.16(Wed); 0.18(Thu)...

Yes, I did. I was just thinking about it in completely the wrong way.

Thank you. You have the patience of a Saint!

OK, So I have ended up with an answer of... Q=(176/3)πDa4 Would really appreciate confirmation either way. Thank you so much for your help, I really appreciate it.

Its ok, I know I am wrong there, integration by parts!