How long will the sun shine for? (relativistic energy)

  • #1
ElijahRockers
Gold Member
270
10

Homework Statement



The sun radiates about 4.0E26 J/s.

a) How much mass is released as radiation each second?

b) If the mass of the sun is 2.0E30 kg, how long can the sun survive if the energy release continues at its present rate?

Homework Equations



Not sure, but I think I'm supposed to use

ΔE=Δmc2

The Attempt at a Solution



a)

Δm = ΔE/c2
Δm = 4.0E26/c2 = 4.44E9 kg/s

b)

2.0E30 kg x (1 s / 4.44E9 kg) =

4.5E20 seconds or
1.42E13 years

Is this correct?
 

Answers and Replies

  • #2
172
2
Yep, I think that's right.
 

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