Pelicans tuck their wings and free-fall straight down whei} diving for fish. suppose a pelican starts its dive from q height of 16.0m and cannot change its path once committed. if it takes a fish 0.20 s to perform evasive action, at what minimum height must it spot the pelican to escape? assume the fish is at the surface of the water.

Several processes form metal ore. match each process to its description. volcanic activity weathering hydrothermal energy rocks break down as they interact with air and water. arrowright density differences and other factors cause metals to concentrate in igneous rocks. arrowright seawater heats up from contact with hot rock, and metals dissolve in it. the water rises and contacts cooler water, causing metal ores to settle on the ocean floor. arrowright

Three charge are arranged as shown in the diagram. the magnitude of the net electrical force acting on the +6 uc charge, rounded to the tenths place, is .

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)