Erica (39 kg ) and Danny (48 kg ) are bouncing on a trampoline. Just as Erica reaches the highest point of her bounce, Danny is moving upward past her at 4.3 m/s. At that instant he grabs hold of her. Required:
What is their speed just after he grabs her?

Matter is needed to transfer thermal energy bya. conductionb. convectionc. radiation d. both a & b.

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

An element becomes a positively charged ion when itloses protons.loses electrons.gains electrons.gains neutrons.