Suppose you have an internet friend who is studying chemistry just like you are. your friend claims the change from liquid water to water vapor is a chemical change. write a brief email that might convince your friend otherwise

Which sound characteristic is not affected by the relative motion of an object

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)

For waves in the ocean, the medium of the waves is a. air b. water c. energy d. a passing boat