Experimental investigation of the behavior of falling disks in water using two synchronized CCD cameras

Authors

Marian F. Baclayon ⋅ PH Department of Physics, University of San Carlos
Rogel Arnel C. Lusares ⋅ PH Department of Physics, University of San Carlos
E. T. R. Palagtiosa ⋅ PH Department of Physics, University of San Carlos
Roland Emerito S. Otadoy ⋅ PH Department of Physics, University of San Carlos

Abstract

The motion of thin plastic disks that were let to fall freely in water was experimentally investigated using two 8-bit CCD cameras which were controlled and synchronized using LabVIEW^®. The disk diameters vary from 1.850–3.110 ± 0.005 cm, with densities ranging from 1.09–1.43 ± 0.05 g/cm³. The two projections of their motion as they fell revealed that they do not fall simply perpendicular to the water surface but swayed sideways (flutter) while rotating along the vertical axis (autorotation). It was found out that the amplitude of fluttering increases with increasing disk diameter, and the autorotation is deduced from the transfer of the fluttering amplitude from one projection to the other. The disks were also found to move with constant velocity downward after they were released as inferred from their position-time graph. The terminal velocities were found to decrease with increasing disk diameter, which is as expected for "drag" effect to be dependent on the object's surface area.

Downloads

Issue

2004: Proceedings of the 22nd Samahang Pisika ng Pilipinas Physics Congress

Article ID

SPP-2004-1D-03

Section

Image and Signal Processing

Published

2004-10-25

How to Cite

[1]

MF Baclayon, RAC Lusares, ETR Palagtiosa, and RES Otadoy, Experimental investigation of the behavior of falling disks in water using two synchronized CCD cameras, Proceedings of the Samahang Pisika ng Pilipinas 22, SPP-2004-1D-03 (2004). URL: https://proceedings.spp-online.org/article/view/SPP-2004-1D-03.