R. Araki, A. Takita, T. Ishima, H. Kawashima, N. Pornsuwancharoen, S. Punthawanunt, E. Carcasona, Y. Fujii
We propose a method for measuring the impact force of a spherical body dropping onto a water surface. The velocity of the center of gravity of a metal spherical body, in which a cube corner prism is embedded so that its optical center coincides with the center of gravity of the sphere, is accurately measured using an optical interferometer. The acceleration, displacement, and inertial force of the sphere are calculated from the velocity. The sphere is also observed using a high-speed camera. The uncertainty in measuring the instantaneous value of the impact force with a sampling interval of approximately 1 ms is estimated to be 8 mN, which corresponds to 0.8% of the maximum force of approximately 1.0 N. © 2014 AIP Publishing LLC.
School of Science and Technology, Gunma University, Kiryu, 376-8515, Tenjin-cho 1-5-1, Japan; Faculty of Industry and Technology, Rajamangala University of Technology Isan, Thanyaburi Pathum Thani 12110, Thanyaburi 39 Muh1, Rangsit-Nakhonnayok Rd. Klong Hok, Thailand; Faculty of Science and Technology, Kasem Bundit University, Suanluang Bangkok 10250, 1761 Pattanakarn Rd., Thailand; Faculty of Engineering, University of San Carlos, Cebu City 6000, P. del Rosario Street, Philippines
