This study investigates the oscillatory motion of a rocking solid semi-cylinder to determine whether it exhibits simple harmonic motion (SHM) and to characterize its damping behavior. Using a theoretical framework derived from classical mechanics, the experiment aims to verify the independence of the oscillation period from amplitude, compare experimental and theoretical natural frequencies, analyze the sinusoidal nature of angular displacement over time, and quantify the system’s damping coefficient. The experimental setup involved tracking the motion of a semi-cylinder displaced by small angles using video analysis and computational tools. The results confirm that the oscillation closely follows SHM principles, with a nearly constant period and frequency. The damping coefficient, relaxation time, and quality factor (Q-value) were also determined, indicating that the system exhibits underdamped oscillatory motion. These findings contribute to a deeper understanding of the dynamics of rocking semi-cylinders and their practical applications in mechanical and engineering systems.