When a solid cylindrical bar free at both ends is suspended by loops of thread, damping is greatly reduced, and many precise longitudinal and lateral (flexural) frequencies, can then, be readily observed. The standard equation for flexural vibration frequencies is inaccurate for the higher modes, so the corrections proposed by Rayleigh and Timoshenko must be considered. By incorporating these corrections, the author has developed an approximation that agrees well with experiment and gives an idea of Poisson's ratio for the bar. (c) 2005 American Association. of Physics Teachers.
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