Which of the following describes water? a. is a substance that dissolves only a few other substances; has weak cohesive forces between molecules. b. is a substance that dissolves only a few other substances; has strong cohesive forces between molecules. c. is a substance that requires a small amount of energy per gram to raise its temperature; has strong cohesive forces between molecules. d. is a substance that requires a large amount of energy per gram to raise its temperature; has strong cohesive forces between molecules.

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)