HOLOGRAPHIC STUDY OF A VIBRATING BELL - AN UNDERGRADUATE LABORATORY EXPERIMENT

An experiment combining holography and musical acoustics is described. Structures of vibration modes of a bell are visualized by time-averag e holography under either acoustical or mechanical excitation. The vib ration amplitude as measured by an accelerometer shows very good quant itative agreement with that determined from our holograms by fringe co unting. An effect of degenerate level separation is shown in the mecha nical case. It is argued that this experiment is not only very inexpen sive for a physics laboratory already equipped for holography, but tha t it also strongly stimulates students to deepen their insight into a variety of different topics in applied physics. (C) 1998 American Asso ciation of Physics Teachers.