Archived Estimate nuclear energy generation rate (formula given) per unit MASS MASS?

AI Thread Summary
The discussion revolves around estimating the nuclear energy generation rate for the proton-proton (pp) cycle in the Sun using a provided formula. The user correctly substituted values into the formula and calculated an energy generation rate of 3.186 x 10^-4 W kg^-1. However, confusion arises regarding the phrase "per unit mass mass," which seems to be a typographical error. Clarification indicates that W/kg is appropriate for the problem statement, suggesting that the user’s calculation is indeed correct. The focus remains on understanding the application of the formula in the context of stellar fusion processes.
daleklama
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Homework Statement



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.


Homework Equations



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

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 haven't a clue about... did I do it wrong?

Thanks for any help!
 
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W/kg is fine if the problem statement is "per unit mass" (or "per unit mass mass" which looks like a typo).
 
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