Total energy of the sun problem

Catsmokinpot

I have to calculate the total energy output by the sun every second,

The sun's temperature is given as 5770K
its radius is 6.96x10^8m

I decided to use Stephan Boltzmann's law but I don't know if I'm right

I used J=AσT^4 where the A is the area of the sun 4πr^2, T is the absolute temperature and σ is Boltzmann's constant (1.38x10^-23)

I got 8.08x10^8 Joules/sec, am I way off? I have looked but can't find a figure for it.

Improbable

From wikipedia:

The proton–proton chain occurs around 9.2×10^37 times each second in the core of the Sun. Since this reaction uses four free protons (hydrogen nuclei), it converts about 3.7 × 10^38 protons to alpha particles (helium nuclei) every second (out of a total of ~8.9 × 10^56 free protons in the Sun), or about 6.2 × 10^11 kg per second.[37] Since fusing hydrogen into helium releases around 0.7% of the fused mass as energy,[38] the Sun releases energy at the mass-energy conversion rate of 4.26 million metric tons per second, 384.6 yottawatts (3.846×10^26 W)

ChocolateSauce

Improbable wrote: »

From wikipedia:

The proton–proton chain occurs around 9.2×10^37 times each second in the core of the Sun. Since this reaction uses four free protons (hydrogen nuclei), it converts about 3.7 × 10^38 protons to alpha particles (helium nuclei) every second (out of a total of ~8.9 × 10^56 free protons in the Sun), or about 6.2 × 10^11 kg per second.[37] Since fusing hydrogen into helium releases around 0.7% of the fused mass as energy,[38] the Sun releases energy at the mass-energy conversion rate of 4.26 million metric tons per second, 384.6 yottawatts (3.846×10^26 W)

And that means that it emits millions of tonnes of light every second, which is awesome.
:pac:

Tears in Rain

Catsmokinpot wrote: »

I have to calculate the total energy output by the sun every second,

The sun's temperature is given as 5770K
its radius is 6.96x10^8m

I decided to use Stephan Boltzmann's law but I don't know if I'm right

I used J=AσT^4 where the A is the area of the sun 4πr^2, T is the absolute temperature and σ is Boltzmann's constant (1.38x10^-23)

I got 8.08x10^8 Joules/sec, am I way off? I have looked but can't find a figure for it.

You're using the wrong constant, you should be using the Stefan-Boltzmann constant instead of the Boltzmann constant.

If you use the Stefan-Boltzman constant (value of roughly 5.67 * 10^-8 ) you get the correct answer...

del88

Seen brian cox doing something similar in "wonders of the solar system"

https://www.youtube.com/watch?v=12Zj7Bux5Bs

derry

That video requred for me two looks to get what he was saying

What a lot of watt the sun produces

Derry