An automobile is cruising along a level highway steadily at 62 miles/hr. The onboard computer indicates a fuel economy of 26 miles/gal. The engine is operating at an air fuel ratio of 14.7 (mass basis). The density of the fuel is 860 kg/m³. 

(i) Assuming the exhaust gases have a molecular weight of 28.5 kg/kmol and a temperature of 580 K, determine their velocity in the 50-mm-diameter exhaust pipe. The exhaust pressure is nominally 100 kPa. 

(ii) Considering the automobile and its contents to be the open system (control volume) of interest, determine the time rate of change of the system mass, dMcv/dt. 

(iii) Estimate the change in weight of the automobile and its contents in  time it takes to travel 100 miles.