Progressive and stationary waves common mistakes

Common mistakes

• Identifying Nodes and Antinodes

  Students often confuse nodes with antinodes on stationary wave diagrams, mistakenly identifying points of maximum displacement as nodes.

  Fix itRemember that nodes are points of zero displacement, while antinodes are points of maximum displacement. To clarify, observe that at nodes, the wave does not move, and at antinodes, the wave oscillates with the greatest amplitude.

• Misunderstanding the Effect of Tension on Wave Speed

  Students often believe that increasing the tension in a string does not significantly affect the speed of the wave traveling through it.

  Fix itTo understand the relationship, use the wave speed formula: v = √(T/μ), where v is the wave speed, T is the tension, and μ is the mass per unit length. When tension increases, wave speed increases. For example, if T = 100 N and μ = 0.5 kg/m, then v = √(100/0.5) = √200 = 14.14 m/s. Thus, the wave speed increases with tension.