A satellite is powered by a small nuclear generator that puts out 10 W.How much matter is converted into energy over the 20-year life span of the generator?
A)70 µg
B)70 g
C)7 g
D)7 kg
E)4 mg

Question

A satellite is powered by a small nuclear generator that puts out 10 W.How much matter is converted into energy over the 20-year life span of the generator?
A)70 µg
B)70 g
C)7 g
D)7 kg
E)​4 mg

Quizplus · Accepted Answer

The energy output can be calculated using the formula derived from Einstein's equation, E=mc^2, where E is energy, m is mass, and c is the speed of light. First, calculate the total energy output over 20 years: 10 W * 20 years * 365.25 days/year * 24 hours/day * 3600 seconds/hour = 6.3072 * 10^9 J. Then, rearrange the formula to solve for m: m = E/c^2. Using c = 3.00 * 10^8 m/s, m = 6.3072 * 10^9 J / (9 * 10^16 m^2/s^2) = 7.008 * 10^-8 kg, or 70 µg.

A Satellite Is Powered by a Small Nuclear Generator That