How do you find the velocity of a wave?

Write the equation for momentum, first using symbols for the variables, then using words for the variables.

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

Which is the most accurate name for the covalent compound p2o3?