astronomy

The total mass of the Sun is about 2 x 10^{30} kg, of which about 75% was hydrogen when the Sun formed. However, only about 13% of this hydrogen ever becomes available for fusion in the core. The rest remains in layers of the Sun where the temperature is too low for fusion.

1. Based on the given information, calculate the total mass of hydrogen available for fusion over the lifetime of the Sun. ? answer should be _______kg

2. Combine your results from part A and the fact that the Sun fuses about 600 billion kg of hydrogen each second to calculate how long the Sun's initial supply of hydrogen can last. Give your answer in both seconds and years. ? answer should be _______s AND ________years

1) ((2 x 10^30) x .75)) x .13) = 1.95 x 10^29 kg

2) (1.95 x 10^29)/600,000,000,000 = 3.25 x 10^17 seconds = 1.03 x 10^10 years