Which two descriptions would you use to describe a distance-and-time graph? a
It illustrates a change in speed
b
Time is graphed on the y-axis and distance is graphed on the x-axis
c
Time is graphed on the x-axis and distance it graphed on the y-axis.
d
It illustrates changes in position
.

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)