Q: Assume that the entire mass of the Sun, 2 x 10^(30) kg, was gasoline, and ignore the required oxygen. How long could the Sun continue to burn at its current rate? Express your result in seconds, and in years. The lifetime would be the ratio of initial mass to the rate at which mass is used: initial mass (kg) lifetime = ------------------- rate of use (kg/s) 2 x 10^(30) kg = ----------------- 8.7 x 10^(18) kg/s = 2.3 x 10^(11) s = 7300 years