The sun radiates energy at the rate of 3.92x 10^26 W. (a) What is the change in the sun's mass in one second? (b)How much mass does the sun lose in the lifetime of your average earthling (say, 75 years)?

Answer 1

Use the relationships

1 watt = 1 Joule / second

E = mc^2

E = energy, m = mass, c = speed of light (3*10^8 m/s)