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Question
It has been found that the Sun’s mass loss is 4.34 × 109 kg per second. How much energy per second would be radiated into space by the Sun?
Solution
Given: Sun’s mass loss = 4.34 × 109 kg per second
To find: Energy radiated per second into space by Sun
Calculation: Δm = 4.34 × 109 kg per second
Now, 1.66 × 10-27 kg = 1 u
∴ Δm = `(4.34 xx 10^9)/(1.66 xx 10^-27)` u per second
= 2.614 × 1036 u per second
Now, 1 u = 931.4 MeV
∴ 2.614 × 1036 u per second = 2.614 × 1036 × 931.4
= 2.435 × 1039 MeV/s
Now, 1 eV = 1.6022 × 10-19 J and 1 eV = 1 × 10-6 MeV
∴ 1 MeV = 1.6022 × 10-13 J = 1.6022 × 10-16 kJ
∴ E = 2.435 × 1039 MeV/s × 1.6022 × 10-16 kJ/MeV
= 3.901 × 1023 kJ/s
Energy radiated per second into space by Sun is 3.901 × 1023 kJ/s.
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