A boy runs to the bathroom from class that is 30 m away. He starts from rest and flies into the bathroom with a speed of 9 m/s. A) What was his acceleration? B) How long did it take him to make it to the bathroom?

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.