I have this question on this article by G.K. O'Neill,1974. who proposed having a cylindrical habitat in space. Then the article posed a question asking me to ponder on the speed of the rotation of the cylinder such that it wld imitate earth's gravitational field at the walls of the cylinder given that it is 6.07 km in diameter and 30km long. It rotates abt its long axis. My working is as follows but am unsure if I am right cos I dont seem to use the information on the length of the cylinder. radius = 6.07/2km Since rw^2 = 9.8, and w = 2PI * f, where w=angular velocity and f=frequency, we solve for f to get the ans. From what I have the ans for f is 0.009043859 rev/s . am i right? If not any hints? Cos i dont seem to get the ans.