N the metric system the acceleration due to gravity near Earth's surface is about 9.81 meters per second per second. What is the acceleration due to gravity as measured in the English system, that is, in feet per second per second? (Round your answer to one decimal place.)

Which statement best describes the superposition principle? a.) if two in-phase waves arrive simultaneously at a point, their amplitudes add up b.) if two out-of-phase waves arrive simultaneously at a point, their amplitudes add up c.) if two in-phase waves arrive at a point one after another, their amplitudes add up d.) if two out-of-phase waves arrive at a point one after another, their amplitudes adds up