8. Centripetal Forces & Gravitation

The 12,000-kg Lunar Command Module is in a circular orbit above the Moon's surface. If it spends ¼ of its fuel energy ($-1.74\times 10^9$ J) bringing it to a circular orbit just above the surface, how high was its original orbit?

a) How much work do you have to do on a 100-kg payload to move it from Earth's surface to a height of 1000 km?

b) How much additional work must you do to put this payload into orbit at this altitude?