A roller coaster car rapidly picks up speed as it rolls down a slope. As it starts down the slope, its speed is 4 m/s. But 3 seconds later, at the bottom of the slope, its speed is 22 m/s. What is its average acceleration?

Air enters the compressor of a gas turbine power plant operating at steady state at 290 k, 100 kpa and exits at 330 kpa. stray heat transfer and kinetic and potential energy effects are negligible. the isentropic compressor efficiency is 90.3%. using the ideal gas model for air, determine the work input, in kj per kg of air flowing.