80 foot-pounds of work is needed to move the sofa in tyler's apartment. which of the following statements is true? a.) if tyler moves the sofa himself, he will do more work than if he gets a friend to . b.) if tyler and his roommate move the sofa together, they will do half the amount of work. c.) if the sofa does not move, no work is done. d.)all of the above.

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)