Which is the best description of the acceleration of an object? an airplane changes elevation from 10,000 ft to 5,000 ft a cars velocity changes from 25 m/s to 20 m/s in 5 seconds a runner travels 100 m in one minute a remote-control car speeds up to 15 m/s

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.