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 Nuclear and Particle Physics Nuclear and Particle Physics Help Forum Oct 19th 2014, 05:44 PM #1 Senior Member   Join Date: Jun 2014 Posts: 306 rate of hydrogen change into helium i cant understand the solution provided. from the ans given, does the author mean (there are 4 hydrogen atoms) , each one will contribute to E (which is 3.82x10^26 W) In my opinion , E (which is 3.82x10^26 W) should be contributed equally by 4 hydrogen atom ... so for me , each hydrogen atom will only contribute to 1/4 E .... 0.25(4.28x10^-12) ( rate of hydrogen change into helium) = 0.25(3.82x10^26) rate of hydrogen change into helium= 8.92x10^37s^-1   Oct 19th 2014, 06:24 PM   #2
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 Originally Posted by ling233 i cant understand the solution provided. from the ans given, does the author mean (there are 4 hydrogen atoms) , each one will contribute to E (which is 3.82x10^26 W) In my opinion , E (which is 3.82x10^26 W) should be contributed equally by 4 hydrogen atom ... so for me , each hydrogen atom will only contribute to 1/4 E .... 0.25(4.28x10^-12) ( rate of hydrogen change into helium) = 0.25(3.82x10^26) rate of hydrogen change into helium= 8.92x10^37s^-1
There are 4 H atoms that go into making He. In this process energy is released so we need to find out how much energy. We can compute the mass of each element and calculate the energy lost in the fusion process, which is described in the solution.

Now, each H atom gives an energy of 1/4 of this, so (1/4) x 4.28 x 10^(-12) J. So to calculate the rate of H reduction we divide power by the energy of each H atom.

Everything you have said matches this until your second to the last line, which makes no sense:

0.25(4.28x10^-12) ( rate of hydrogen change into helium) = 0.25(3.82x10^26)

This is an impossible equation. The two sides don't equal each other! What are you trying to say here?

-Dan
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