Calculating luminosity given accretion power

natxio
Messages
7
Reaction score
0

Homework Statement



I have a question regarding calculating luminosity given accretion power. I have accretion power given to me as Δm/Δt= 1.5 solar masses/yr, in order to solve for luminosity are we supposed to convert the accretion power into solar masses/seconds or is it just some kind of variable where it doesn't matter. [I have to find the luminosity in Joules/sec]

Homework Equations



Luminosity= η x (Δm/Δt) x c^2


The Attempt at a Solution



My answer would be that I do have to convert because one joule= kg x m^2/ s^2 and if I have to find the Joules/sec I cannot leave the years unconverted.

(sorry if it was a dumb question, I think I answered it myself just working through explaining it to you guys)
 
Physics news on Phys.org
Yes, to get an answer in SI units you have to convert the accretion rate into kg/s through the conversions between solar masses to kilograms, and years to seconds. Then, you can use c in m/s and the efficiency will be a dimensionless number, so you can just multiply through and your answer will be in J/s, as you observed.
 
Thread 'Need help understanding this figure on energy levels'
This figure is from "Introduction to Quantum Mechanics" by Griffiths (3rd edition). It is available to download. It is from page 142. I am hoping the usual people on this site will give me a hand understanding what is going on in the figure. After the equation (4.50) it says "It is customary to introduce the principal quantum number, ##n##, which simply orders the allowed energies, starting with 1 for the ground state. (see the figure)" I still don't understand the figure :( Here is...
Thread 'Understanding how to "tack on" the time wiggle factor'
The last problem I posted on QM made it into advanced homework help, that is why I am putting it here. I am sorry for any hassle imposed on the moderators by myself. Part (a) is quite easy. We get $$\sigma_1 = 2\lambda, \mathbf{v}_1 = \begin{pmatrix} 0 \\ 0 \\ 1 \end{pmatrix} \sigma_2 = \lambda, \mathbf{v}_2 = \begin{pmatrix} 1/\sqrt{2} \\ 1/\sqrt{2} \\ 0 \end{pmatrix} \sigma_3 = -\lambda, \mathbf{v}_3 = \begin{pmatrix} 1/\sqrt{2} \\ -1/\sqrt{2} \\ 0 \end{pmatrix} $$ There are two ways...
Back
Top