The Moon is seen to keep one face toward Earth at all times. If viewed from a point directly above the plane of the planetary system, how does it have to rotate to maintain this alignment?

The percent efficiency of a machine can never be 100% (or greater), because in the real world some energy is always converted into a. heat b. work c. input force d. output force

Explain earth's motion, using the terms "precession" and "rotation" in your answer.

Arigid tank is divided into two equal parts by a partition. one part of the tank contains 3 kg of compressed liquid water at 400 kpa and 60°c while the other part is evacuated. the partition is now removed, and the water expands to fill the entire tank. determine the entropy change of water during this process, if the final pressure in the tank is 40 kpa. use steam tables.