Recent content by mell0r

Wow, there you go. I Don't think I've ever been as happy to see an equation before as i just have haha! Thank you SammyS, gneill and smatik for the fantastic help and for coping with me :-p

Thank you! so the integral would be M=4πRρ0, and therefore ρ0=\frac{M}{4πR}??

so I integrated dM=4πr2ρ0dr over 0 and R, i get M=\frac{4}{3}πR3ρ0 and thus worked out ρ0 from re-aranging that equation. Is that correct so far? I'm finding this so confusing, yet I can do the same derivation for a uniform density perfectly fine..

So overall i'd be performing 3 integration's? What would be the difference between integrating for the mass and the mass as a function? This math seems completely new to me, and i would have Google searched to figure it out, but I'm not even sure what to search.. Sorry for being annoying...

Ah, yes, sorry - i meant to include that. Even so, my mind is completely blank now.. How can i relate that function to my derivation from my ρ0 variable? :confused:

Homework Statement Find the total gravitational potential energy stored in a sphere with a 1/r2 density distribution if the total mass is 6.7 solar mass and the radius is 1.3 solar radius. Express you answer in units of 1041 Joules. The Attempt at a Solution To derive the equation, i...

If it's not moving initially, 0 m/s will be fine.

You should have 2 in your answer as acceleration is the change in velocity (i.e. 60km/h in this case). The 0km/h can be ignored in the case of significant digits :smile:

Thanks for such a sudden reply! :smile: It seems so obvious now, but my mind would just not accept it at the time haha... Thanks to the help of a handy ping pong ball lying around the house it's overcome it though now :-p

Question: The Moon has an albedo of 0.05. What is the total power of the solar radiation reflected from the Moon in units of 10^15 W? My Answer: - To get my answer i multiplied the flux density of the sun measured on the moon, then multiplied it by half of the moon's total surface area...

Hey there! I recently bought said book and would highly recommend it for any Astronomy and Cosmology undergrads. However, one little niggling thing about it (something that grinds my gears in general with textbooks) is that it features end of chapter questions yet no set of answers for the...