What is the maximum speed when the conditions are mass =450 kg, initial height= 30 m, and the roller coaster is initially at rest? A. 30 m/s
B. 24.2 m/s
C. 93.9 m/s
D. 132, 300 m/s

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)