Hans full is pulling on a rope to drag his backpack to school across the ice. he pulls upwards with a force of 22.9 newtons at an angle of 35 degrees above the horizontal to drag his backpack a horizontal distance of 129 meters to the right. determine the work (in joules) done upon the backpack.

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)