An astronomical unit (AU) is a scientific measurement between objects in space. Scientists decided that 1 AU would represent the distance from the Earth to the Sun, about 150 kilometers. Using this information, which objects would exert the strongest gravitational force on each other? A. two objects of the same mass that are 0.08 AU apart
B. two objects of the same mass that are 5 AU apart
C. two objects of the same mass that are 1 AU apart
D. two objects of the same mass that are 12 AU apart

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)