Throughout the rest of the course, we have focused on adding together two physical quantities that combine in fundamentally different ways.\u00a0 We have calculated the total energy of a system by adding together terms that add as scalars.\u00a0 Adding together energy terms is just adding together numbers.\u00a0 We have also calculated the net force acting on an object by adding together forces.\u00a0 Because forces are vectors, we needed to keep track of not just the magnitude of the forces but also their direction as we added them.\u00a0 This module focuses on the third type of object that we need to add together, but that has its own rules for how we need to do it.\u00a0 As two waves pass through each other, they create a resultant wave that we can calculate by adding together the two waves at each point where they overlap.\u00a0 But like vectors, we need to keep track of two quantities when we add waves together, the amplitude of each wave and their phase difference.\u00a0 Similar to the idea that we need to pay attention to magnitude and direction when we add together forces, we need to pay attention to amplitude and phase when we add together waves.<\/p>\n
The relative difference between the phase of two waves will tell us how the waves interfere with each other.\u00a0 When two waves line up perfectly, so that the peaks of the waves line up with each other, they interfere constructively.\u00a0 Two waves can also line up so that the peaks of one wave line up with the troughs of another, they interfere destructively.\u00a0 If two waves don\u2019t interfere constructively or destructively, they exhibit intermediate interference.<\/p>\n\n\t\t\t Candela Citations<\/h3>\n\t\t\t\t\t