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Updated: Aug 21, 2026

Impacts of Free-falling Spheres on a Deep Liquid Pool with Altered Fluid and Impactor Surface Conditions
Published on: February 17, 2019
The interfacial torque on a partially submerged sphere
Pushpendra Singh1, Todd I Hesla
1Department of Mechanical Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA. singhp@njit.edu
Abstract:
For a heavy spherical particle floating at the surface of a liquid, we show that the resultant torque exerted on the particle about its center by the interfacial forces is always zero, regardless of the position and shape of the contact line, provided only that the interfacial tension and the contact angle are constant. Interfacial tension therefore cannot rotate a spherical particle about its center.
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