A steel wire 2.0m is length and 2.0mm inn diameter supports 10-kg mass. What is the stress in the wire?
(a) 3.010 (6) 3.11 N/m² (c) 31N (d) 3.1 x 10'N/m
2

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.