Which one of the following substances is a liquid fuel used in rocket engines?

a. liquid oxygen
b. potassium perchlorate
c. codium nitrate
d. ammonia

Arotating space station is said to create “artificial gravity”—a loosely-defined term used for an acceleration that would be crudely similar to gravity. the outer wall of the rotating space station would become a floor for the astronauts, and centripetal acceleration supplied by the floor would allow astronauts to exercise and maintain muscle and bone strength more naturally than in non-rotating space environments. if the space station is 200 m in diameter, what angular velocity would produce an “artificial gravity” of 9.80 m/s^{2} 2 at the rim?

Which compound is held together by the electrostatic force between two ions? a. co2 b. cci4 c. h2s d. mgf2

Ivana walks 2km north then turns around and walks 3km south