Which of the following devices would you expect to consume the most energy for each hour that it operates?
a. a portable tape recorder
b. an electric space heater
c. a desk lamp
d. an electric can opener

The air in an automobile tire with a volume of 2.60 ft3 is at 70°f and 21 psig. determine the amount of air that must be added to raise the pressure to the recommended value of 30 psig. assume the atmospheric pressure to be 14.6 psia and the temperature and the volume to remain constant. the gas constant of air is ru = 53.34ft⋅lbflbm⋅r(1 psia144 lbf/ft2) = 0.3704 psia⋅ft3lbm⋅r the amount of air that must be added to raise the pressure is lbm