Comparing pitch of sounds
order the sounds made by these sources from highest
to lowest pitch
telephone, piano, motorcycle, lawn mower
lawn mower, motorcycle, piano, telephone
motorcycle, telephone, piano, lawn mower
lawn mower, piano, telephone, motorcycle
125 250 500 1,000 2,000 4,000 8,000
frequency (hz)

The ultracentrifuge is an important tool for separating and analyzing proteins. because of the enormous centripetal accelerations, the centrifuge must be carefully balanced, with each sample matched by a sample of identical mass on the opposite side. any difference in the masses of opposing samples creates a net force on the shaft of the rotor, potentially leading to a catastrophic failure of the apparatus. suppose a scientist makes a slight error in sample preparation and one sample has a mass 10 mg larger than the opposing sample. if the samples are 12 cm from the axis of the rotor and the ultracentrifuge spins at 70,000 rpm, what is the magnitude of the net force on the rotor due to the unbalanced samples? ( be thorough on your answer)

An object resting on a table weighs 100 n. with what force is the object pushing on the table? with what force is the table pushing on the object? explain how you got your answer.

Abowling ball rolling down the lane toward the pins has gravitational potential energy. a. no b. a lot of c. a little