Which of the following best describes a mathematical wave A: A transfer of energy
B: A movement of matter
C: When energy is converted from one form to another
D: A periodic disturbance of a medium

The passage that directs air to the lungs is called a. diaphragm. b. larynx. c. bronchi. d. pharynx.

In which of the following is positive work done by a person on a suitcase

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)