A60 kg rower is paddling a 30 kg canoe with a 2 kg paddle at a constant speed of + 10 m/s. if she loses her grip on the paddle and it flies backward with a velocity of -20 m/s, what is the final momentum of the boat and rower?
a) +10 kg-m/s
b) +10.7 kg-m/s
c) +960 kg-m/s
d) +975.2 kg-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.