Standing waves

Understandings:

• The nature of standing waves
• Boundary conditions
• Nodes and anti-nodes

Applications and skills:

• Describing the nature and formation of standing waves in terms of superposition
• Distinguishing between standing and travelling waves
• Observing, sketching and interpreting standing wave patterns in strings and pipes
• Solving problems involving the frequency of a harmonic, length of the standing wave and the speed of the wave

Guidance:

• Students will be expected to consider the formation of standing waves from the superposition of no more than two waves
• Boundary conditions for strings are: two fixed boundaries; fixed and free boundary; two free boundaries
• Boundary conditions for pipes are: two closed boundaries; closed and open boundary; two open boundaries
• For standing waves in air, explanations will not be required in terms of pressure nodes and pressure antinodes
• The lowest frequency mode of a standing wave is known as the first harmonic
• The terms fundamental and overtone will not be used in examination questions