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)?

1 answer

(a) Use Einstein's equation
E = m c^2

The mass loss rate is
1/c^2 * (Energy loss rate)

(b) Mass loss = (Mass loss rate)* T
where T = 75 years, expressed in seconds

75 y = 2.37*10^9 s
Use the mass loss rate that you calculate for (a)