Whoever does this will be marked as the brainliest.
Hydrogen accounts for 71% of the Sun's mass today. If only one-tenth of that Hydrogen burns into Helium, how long could the Sun keep shining at its present luminosity? Note that Hydrogen fusion has an efficiency of about 0.7%. Please give your answer in units of years.
Answers
The amount of mass available in the Sun to be used as "fuel" is the mass in the core of the Sun, which is approximately 10% of its mass. (The mass of the Sun is 2 x 1030 kg.) Recall that, each time four hydrogen nuclei fuse into a helium nucleus, 0.7% of the mass of hydrogen is converted into energy (where E = mc^2).
You can put these numbers together to figure out the total amount of energy that the Sun can produce in its hydrogen-burning lifetime.
The Sun loses energy at rate of 3.78*1026 Joules/second, and if it has 1.26*1044 Joules of available energy, then we can divide the two to determine how long the Sun can shine: (3.78*1026 Joules/second)/(1.26*1044 Joules)=3.33*1017 seconds. We should convert this to more apropriate units of years, 3.33*1017 seconds/(60 sec/min*60 min/hr*24 hr/day*365 day/year)=1.05*10^10 years or 10.5 billion years.
Plz mark me as brainliest bcz it took a lot of time to give u the answer.
hope it helps