an insulated rigid tank initially contains 1.5lbm of helium at 75F and 50psia. A paddle wheel with a power rating 0.03hp is operating within the tank for 45 minutes. the specific heat at constant volume (Cv) for helium is 0.753 BTU/(lbm-oF). Determine the a) amount of paddle wheel work in Btu after 45mins b) final temperature c) final pressure of the helium gas.