From where is the origin of roller coasters believed to have come from?

What is the magnitude of the resultant vector round your answer to the nearest tenth

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

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