Question

Assume the Sun has been producing energy at a constant rate (3.78 x 10 ^26 J/s) over its lifetime of 4.5 billion years. How much mass has it lost creating energy over its lifetime?

____________ kg

Answer 1

E = mc²

3.78 x 10 ^26 J = m *(3*10^8m/s)^2         

m = 4.2*10^9 kg

Thus mass = 4.2*10^9kg required per second

Let us calculate for t= 4.5 billion years = 1.4*10^17s

m= 4.2 x 10⁹ kg/s x 1.4 x 10¹⁷ s = 5.88 x 10²⁶ kg

For 4.5 billion year mass= 5.88 x 10²⁶ kg required