Which atmospheric gas is used by plants and given off by animals? A. Carbon dioxide. B. Nitrogen C. Oxygen D. Argon

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)

On a hot saturday morning while people are working inside, the air conditioner keeps the temperature inside the building at 22degreesc. at noon the air conditioner is turned off, and the people go home. the temperature outside is a constant 33degreesc for the rest of the afternoon. if the time constant for the building is 4 hr, what will be the temperature inside the building at 4 : 00 font size decreased by 2 upper p . font size decreased by 2 upper m .? at 6 : 00 font size decreased by 2 upper p . font size decreased by 2 upper m .? when will the temperature inside the building reach 24degreesc? 324281

Another word for electromagnetic energy is a. heat b. force c. matter d. radiation