Video Analysis of an Oscillating Cantilever for Introductory Laboratories

Abstract

A wood cantilever of length ∼2.5 m is driven into resonance using the hand as a simple driver. Video recordings of these oscillations are analyzed to determine experimental second harmonic ( n = 2) damped resonance frequencies. These frequencies are compared to theoretical ones, obtained from measurements of elastic moduli, damping properties, and physical dimensions of the cantilever. Experimental frequencies agree with theoretical ones to within their respective uncertainties. Experiments described here can be incorporated seamlessly into introductory college physics laboratories, following discussions of simple harmonic oscillators (including damping). These kinds of experiments are useful for developing students’ skills in designing and troubleshooting experiments, analyzing video recordings, and modeling data using computers. The ease of set up and simple apparatus also make these activities ideal for remote learning such as during the recent COVID-19 pandemic.