In this work. the response of a ship rolling in regular beam waves is studied. The model is one degree of freedom model for nonlinear ship dynamics. The model consists of the terms containing inertia. https://www.roneverhart.com/Western-Digital-Ultrastar-DC-HC570-WUH722222ALE6L4-0F48155-22TB-7-2K-RPM-SATA-6Gb-s-512e-SE-3-5in-Refurbished-HDD/