(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Consider energy generation in the Sun. Fusion through the pp cycle takes place within its core which has

r = 0.2 Rs

T = 1.3 x 10 ^ 7 K

rho (density) = 1.1 x 10 ^ 5 kg m^-3

X (total mass fraction of hydrogen) = 0.34

The nuclear energy generation rate for the pp cycle (where T6 = T/10^6K and density has units of kg m ^ -3) is

Epp = (0.241) (rho) (X^2) (T6 ^ (-2/3) ) exp (-33.8/(T6 ^ 1/3)) W kg ^ -1

Estimate epp per unit mass mass.

2. Relevant equations

Epp = (0.241) (rho) (X^2) (T6 ^ (-2/3) ) exp (-33.8/(T6 ^ 1/3)) W kg ^ -1

3. The attempt at a solution

I subbed everything in:

Epp = (0.241) (1.1 x 10 ^ 5) (0.1156) ( 13 ^ -2/3) exp (-33.8/ (13 ^ 1/3))

(T6 is 13, because it says in the question that T6 = T/10^6K)

and I got 3.186 x 10 ^ -4 as my final answer, I assume the unit is W kg ^ -1 because it was given in the formula.

The bit I'm confused by is that in the question it specifies "estimate epp PER UNIT MASS MASS."

That bit I havent a clue about... did I do it wrong?

Thanks for any help!

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Archived Estimate nuclear energy generation rate (formula given) per unit MASS MASS?

Have something to add?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**