How fast must a plane fly along the earth's equator so that the sun stands still relative to the passengers? give your answer in both km/h and mph. the radius of the earth is 6400 km.
part a km/h
part b mph
part c in which direction must the plane fly, east to west or west to east?
express your answer using two significant figures.

In a closed system, the total energy prior to an energy transformation is the total energy after. a. equal to b. unrelated to c. greater than d. less than

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)

Can you receive a shock severe enough to prevent you from releasing the wire from an ordinary outlet with dry hands? a. no b. yes explain