Two wave of same amplitude , velocity and frequency travelling in opposite direction superpose to form stationary wave. Know the resulting wave well enough. How the two waves are like at any moment is not necessary . The resulting waveform must be known completely. Some points about the resultant waveform.
1. Amplitude differ : largest at antinode and zero at node
2. Same phase: Every particle between 2 nodes have the same phase .
3. Antiphase: Particles that are in phase are antiphase with particles in the adjacent nodes (segments)
4. Same period: Except for the nodes, every particle have the same period.
5. Velocity differ: Particles have the largest velocity at the antinode (at equilibrium - SHM )
6.In longitudinal wave the high pressure occurs at the node and low pressure at the anitnode. *See next entry
