A paddle wheel is inserted in a 0.6 m^3 rigid, well-insulated tank which is filled with 2 kg of air. The paddle wheel transfers 10 W to the air constantly for 1 hour. You may assume there is no change in both potential and kinetic energy in the tank. Find the (a) energy transfer by work (kJ) and (b) the change in specific internal energy of the air (kJ/kg).