In 1971, U. S. astronaut David Scott conducted a simple yet famous experiment on the surface of the moon, where gm = 1.62 m/s² is the magnitude of the gravitational
acceleration, and there is no atmosphere. Specifically, he dropped a hammer and a feather
from rest at the same height above the ground. Assuming that he released the hammer
from a height 1.55 m above the moon's surface, how fast was the hammer moving when
it hit the ground?
A) 0.98 m/s
B) 1.38 m/s
C) 1.91 m/s
D) 2.24 m/s
E) 5.02 m/s

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)