Destructive Interference & Node & Out of Phase
If two waves of equal amplitude approach each other on opposite sides of the rope, they interfere destructively; that is, the waves destroy each other for the instant they are occupying the same point of the rope and a node is created at that point. A node is a point of no displacement, in this case resulting in a flat rope. Waves are out of phase when they interfere destructively. Once again, after the waves pass through each other, they continue moving as if they never interfered.