In your neighborhood, people are setting up a downhill soapbox derby race. As a safety measure, bales of hay are set up at the bottom of the hill as a barricade to stop cars and drivers. At what point on the car’s path will it have the most kinetic energy? A) at the very top of the hill B) at the midpoint of the hill C) at the very bottom of the hill D) after it collided with the hay

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.