Abstract
Using the constructed Lagrange function \(L\) and calculated dissipative function \(\dot {Q}\) , a general system of dynamic equations has been obtained to describe the motion of a cylindrical body completely immersed in a fluid. It is assumed that the body is hinged at its one end where the origin of coordinates is selected. The free end can make almost any motions and is elastically held by a spring at an arbitrary point. The problem is solved in a spherical coordinate system in which differential equations of motion are derived in terms of two independent angular variables \(\theta \) and \(\varphi \) taking into account the viscosity \(\eta \) of a continuum.
