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

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SUMMARY

The sun radiates approximately 4.0E26 J/s, resulting in a mass loss of 4.44E9 kg/s based on the equation ΔE=Δmc². Given the sun's total mass of 2.0E30 kg, it can sustain its current energy output for about 4.5E20 seconds, which translates to approximately 1.42E13 years. This calculation confirms the sun's longevity under its present energy release rate.

PREREQUISITES
  • Understanding of Einstein's mass-energy equivalence (ΔE=Δmc²)
  • Basic knowledge of units of energy (Joules) and mass (kilograms)
  • Familiarity with astronomical scales of time (years, seconds)
  • Concept of stellar energy output and its implications
NEXT STEPS
  • Explore advanced concepts in stellar evolution and lifecycle
  • Research the implications of mass-energy conversion in astrophysics
  • Learn about the sun's energy generation processes, including nuclear fusion
  • Investigate the long-term effects of stellar radiation on surrounding celestial bodies
USEFUL FOR

Astronomy students, astrophysicists, educators, and anyone interested in the longevity and energy dynamics of stars.

ElijahRockers
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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?
 
Physics news on Phys.org
Yep, I think that's right.
 

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