Investigation of the effects of damping and forcing on the motion of a torsion pendulum
Scientific Study from the year 2013 in the subject Physics - Mechanics, printed single-sided, grade: -, University of Cambridge, language: English, abstract: The harmonic motion of a torsion pendulum under the action of damping and driving forces and the effect of these forces on the quality factor of the oscillation was examined in order to test the theory of harmonic oscillators. The pendulum was equipped with a driving motor as well as an eddy brake. The procedure consisted of two parts, first looking at the unforced and then the forced response, both at two different degrees of damping. Qualitatively, it was found that the behaviour agrees with the theory as the damped response decays exponentially and the amplitude against frequency plot of the forced case shows a well-defined resonance peak at a frequency close to the natural frequency, which was measured to be 0 = 3.306 ± 0.006 s 1. It was found that the quality factor of the undamped and damped free response are 62 ± 2 and 2.0 ± 0.3 respectively. This confirms the fact that a better oscillator has a greater quality factor. The corresponding quality factor of the forced response with the same degree of damping as the latter was determined as 9.7 ± 1.8.