Dancers experience large forces associated with the jumps they make. for example, when a dancer lands after a vertical jump, the force exerted on the head by the neck must exceed the head’s weight by enough to cause the head to slow down and come to rest. the head is about 9.4% of a typical person’s mass. video analysis of a 67 kg dancer landing after a vertical jump shows that her head slows down from 4.2 m/s to rest in a time of 0.19 s.

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

Two trains leave a station at the same time, train a travels at a constant speed of 16 m/s. train b starts at 8.0 m/s but accelerates constantly at 1.0 m/s squared. after 10.0 seconds, which train has the greater speed?

The photo above shows oil and vinegar in a pitcher. the top make a claim about about the density of the vinegar compared to the density of the oil summarize the evidence to support the claim and explain your reasoning