9. Which of the following is a false statement?
A) Sounds waves are longitudinal pressure waves
B) Sound can travel through a vacuum
C) Light travels much faster than sound
D) The transverse waves on a vibrating string are different from sound waves
E) "pitch" (in music) and frequency have approximately the same meaning

An isotope undergoes radioactive decay by emitting radiation that has a –1 charge. what other characteristic does the radiation have?

4. if you were an astronaut on the moon, what would you experience? what would you see from your perspective?

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)