Measurement of the Coefficient of Restitution and Energy Loss in the Collision of Spherical Objects with a Fixed Surface

Document Type : Original Article

Authors
Department of Physics, Qo. C., Islamic Azad University, Qom, Iran
10.22034/jmrph.2026.137631.1001
Abstract
The coefficient of restitution is one of the most important parameters in collision mechanics and plays a significant role in the analysis of elastic and inelastic impacts, dynamic system modeling, and engineering design. In this study, a method for measuring the coefficient of restitution and the energy dissipated from the collision of spherical bodies with a fixed surface, and its relationship with the impact angle, was experimentally investigated. First, the relations among these quantities and the measurable quantities were derived from the conservation laws and the equations of motion and collision; then, by designing an experiment, a single steel spherical ball (a chrome-steel bearing, 1 cm radius, 7.8 g mass) was released from a fixed height and made to collide, at impact angles of 10–65°, with two steel surfaces of different alloy composition, and the coefficient of restitution and the percentage of dissipated energy were calculated for both surfaces. The results showed that, besides the materials’ mechanical properties, the coefficient of restitution depends on the contact conditions and the impact angle, and a lower coefficient of restitution corresponds to greater energy dissipation. The experimental trends of the coefficient of restitution and the dissipated energy with impact angle are reported together with their measurement uncertainties. The proposed approach provides a simple and effective experimental framework for evaluating collision behavior and can be applied in impact mechanics, shock absorption systems, rigid-body dynamics, and undergraduate physics laboratories.
Keywords

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