Aswimmer heads directly across a river, swimming at 1.00 m/s relative to still water. he arrives at a point 41.0 m downstream from the point directly across the river, which is 73.0 m wide. what is the speed of the river current?

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.