What is the purpose of the commutator in an electric motor?

Amarble, a bowling ball, a basketball, and a baseball are rolling across the floor at 10 m/s. which one has the greatest kinetic energy? the marble the bowling ball the basketball the baseball

Determine the age of a fossil if it had only one eighth of its original carbon-14 content remaining?

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