Volume of nebula needed to form a star with same number of atoms as sun

[cattons3]

1. Question: In one region of a nebula the mean separation of atoms is 2.3x10^-3 m. What volume of the nebula contains enough atoms to make a star, similar to the sun, of radius 7.0x10^8 m within which the mean distance between atoms is 1.0x10^-10m?



2. Volume of sphere 4/3(pi(r^3 ))


3. Volume sun = 1.4x10^27 m^3. I thought that atoms in sun would be volume divided by separation distance and therefore volume of nebula that contains same number of atoms is atoms times separation distance (of nebula)? my answer was 3.22x10^34 m^3 answer in book is 1.8x10^49 m^3

I really hate these OCR A2 physics books because they don't work through any of the questions..
Help please!

 

[Ilon]

I agree i had the exact same question and objection to the books, i arrived at the same conclusion as you, did you ever resolve the question?

 

[cattons3]

I'm sorry that was a while ago now and I can't remember ...

 

[Ilon]

HAha fine, I'l go over it with my tutor tomorrow. Well done for putting your working so clearly, it helped.