On an amusement park ride, riders stand inside a cylinder of radius 6.4 m. At first the cylinder rotates horizontally. Then after the cylinder has acquired sufficient speed, it tilts into a vertical plane, as shown in the diagram.
When the ride is oriented vertically, what is the minimum period of rotation that will keep riders from falling?

Air enters a gas turbine with two stages of compression and two stages of expansion at 100 kpa and 17°c. this system uses a regenerator as well as reheating and intercooling – the intercooler returns the air to the inlet temperature. the pressure ratio across each compressor is 4 ; 300 kj/kg of heat are added to the air in each combustion chamber; and the regenerator operates perfectly while increasing the temperature of the cold air by 20°c. determine the system’s thermal efficiency. assume isentropic operations for all compressor and the turbine stages and use constant specific heats at room temperature. (0.378)