How is the energy generated in the sun like stars?

1 Answer
Feb 26, 2016

Nuclear Fusion.

Explanation:

Fusion is responsible to generate Energy in Stars. This can be easily explained by Einstein's Equation.

#E = m* c^2#

In the Core of Stars Fusion reaction fuses two hydrogen atoms into one helium atom. The question is how this reaction gives rise to energy. Turns out the energy comes from the difference of masses between hydrogen and helium.

mass of 1 Hydrogen Atom = 1.00794 u

mass of 1 Helium Atom = 4.002602u

Where,

u = 1.6605 x #10^-27# kg

Now the difference in mass is calculated by #Delta#m = #4m_"H" - m_"He"#.

#Delta m# = 4.03176 - 4.002602
#Delta m# = 0.029158u

#Delta m # = 0.029158 ( 1.6605 x #10^-27#)
#Delta m # = 4.8416859 x #10^-29# kg.

Now by using Einstein's Equation we can calculate the Energy generated by a single fusion reaction.

#E = m*c^2#

Where m = #Delta m#

E = 4.8416859 x #10^-29# * #( 3 x #10^8)^2#

E = 4.35751731 x #10^-12# J.

Now the Luminosity of the Sun is 3.8 x #10 ^26# watts.

So, How many fusion reactions are needed to get to such big number??

This can be calculated by.

n = Luminosity / Energy of one Reaction.

n = 3.8 x #10^26# / 4.35751731 x #10-12#

n = 8.72056203 x #10^37# Reactions Per second are required to generate Sun's luminosity.