Quantum Physics Uni question

[free4spirit]

Hi Everyone

 

Hope all is well with you all, wherever in the world you are....and also happy day to you all

 

I've got a question for my uni assignment that i'm having problems with....I just literally hit the wall....my brain doesn't seem to be able to process the question...or want too...

and I have now been staring blankly at this question for the best part of the afternoon.....and i dont have a clue where to start !

also i was expecting there to be an example of this question in our book....but there wasn't sadly....

so if someone out there has any spare time and can give a girl a hand, it would be hugely appreciated !!

 

ok..... said question;

 

The total power output of the Sun is about 3.8 × 10²⁶ W, and the power-producing core has a radius of about 1.4 × 10⁵ km (about 20% of the full radius of the Sun).

 

Using these figures and knowledge of the energy release in the proton– proton chain; estimate the power density (i.e. the number of watts per cubic metre) in the core of the Sun, and the number of helium nuclei formed per second per cubic metre. Give your answer in scientific notation and to two significant figures.

 

(You may also need to refer to the relationship between the joule and eV, and you will also need to know that the volume, V, of a sphere with radius, r, is V = 4/3πr3 .)

 

If someone could help me start it off or give me an example i would really really appreciate it ... !

 

Many many thanks,

 

Axx

Edited August 21, 2011 by free4spirit

[swansont]

You have the energy released per reaction that produces He, and if all the power (energy/time) is generated in the core, can you find out the rate at which the p-p chain is producing He?

[timo]

Have you really been given this homework assignment in a university course on Quantum Physics?