According to the most widely accepted scientific explanation, how did the universe begin? a. as a collection of protons and neutrons b. as a cloud of gas and dust c. with a huge collision d. with a giant expansion

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