PURPOSE: To show that no reflection occurs when the impedance of the load (absorber at right) matches the impedance of the wave machine.

DESCRIPTION: Adjust the impedance of the absorb-o-matic to eliminate any partial reflection of the incoming wave. The impedance of the absorb-o-matic can be changed by adjusting the string tension. The photographs at the center and right above show the relected pulse before and after the tension of the absorber is properly adjusted.

SUGGESTIONS: The manual written by Shive contains excellent information on both the theory and the use of the wave machine; copies are available in the Lecture-Demonstration office.

REFERENCES: (PIRA 3B22.30)See Demonstration Reference File for further information and experiments.

EQUIPMENT: Shive Wave Machine with dashpot.

SETUP TIME: None.