The Sun radiates electromagnetic energy at the rate of 3.92 × 1026 W. The mass of the Sun is 1.99 × 1030 kg. What fraction of the Sun’s mass is lost during a human lifetime of 75 years? A. 2.16 × 10–13 B. 1.42 × 10–14 C. 6.90 × 10–14 D. 5.18 × 10–12 E. 8.63 × 10

Respuesta :

Answer:

D. 5.18 x 10⁻¹²

Explanation:

[tex]\frac{dE}{dt}[/tex] = rate at which sun radiates energy = 3.92 x 10²⁶ W

M = mass of sun = 1.99 x 10³⁰ kg

[tex]\frac{dm}{dt}[/tex] = rate at which sun's mass is lost

c = speed of light

Energy is given as

E = m c²

Taking derivative both side relative to "t"

[tex]\frac{dE}{dt}=c^{2}\frac{dm}{dt}[/tex]

[tex]3.92\times 10^{26}=(3\times 10^{8})^{2}\frac{dm}{dt}[/tex]

[tex]\frac{dm}{dt}[/tex] = 4.4 x 10⁹ kg/s

t = time interval = 75 yrs = 75 x 365 days = 75 x 365 x 24 hours = 75 x 365 x 24 x 3600 sec = 2.4 x 10⁹ sec

[tex]m[/tex] = mass lost

mass lost is given as

[tex]m = t\frac{dm}{dt}[/tex]

[tex]m = (2.4\times 10^{9})(4.4\times 10^{9})[/tex]

m = 10.56 x 10¹⁸ kg

fraction is given as

fraction = [tex]\frac{m}{M}[/tex]

fraction = [tex]\frac{10.56\times 10^{18}}{1.99\times 10^{30}}[/tex]

fraction = 5.18 x 10⁻¹²