Free boundary condition

Definition

A free boundary condition occurs when a wave encounters a boundary that does not restrict its motion, allowing the wave to reflect without inversion. This is typically seen at the end of a medium where it is free to move.

5 Must Know Facts For Your Next Test

1. Under a free boundary condition, the reflected wave maintains the same phase as the incident wave.
2. It commonly occurs at an open end of a string or an air column.
3. Mathematically, it implies that the derivative of the displacement with respect to position is zero at the boundary.
4. Free boundary conditions are essential in determining standing wave patterns and resonance frequencies.
5. In contrast to fixed boundaries, free boundaries do not invert the waveform upon reflection.

Review Questions

• What happens to the phase of a wave when it reflects off a free boundary?
• How does a free boundary condition affect standing waves on a string?
• Describe what happens at an open end of an air column in terms of wave reflection.

Related terms

Fixed Boundary Condition: Occurs when a wave encounters a rigid or immovable end, causing the reflected wave to invert in phase.

Standing Wave: A pattern formed by the superposition of two traveling waves moving in opposite directions with equal amplitude and frequency.

Resonance: The phenomenon where a system oscillates with greater amplitude at specific frequencies known as resonant frequencies.