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

[SIZE="2"]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...