Shive Wave Machine - Partial Reflections
To show that a wave will be partially reflected at a point where the impedance changes.
Two connected segments of the Shive Wave Machine; dashpot for end if desired.
Partial reflection can be produced by (1) linking the two different segments as shown in the photograph, (2) adding weights to the end of a central crossarm to produce an impedance glitch, or (3) attaching the dashpot at a central location and adjusting it for partial absorption of the incoming wave.
B. A. Burgel, Dispersion, Reflection, and Eigenfrequencies on the Wave Machine, AJP 35, 913-915, (1967).