Determination of fluid force resisting to rigid body motion

The paper investigates added mass quantity or, in other words, fluid inertia moment by which fluid resists to the change of its velocity. Fluid, as any other rigid substance, resists to the change of its velocity. In rigid substances the resistance equals the mass of rigid body while in fluids that mass cannot be known in advance, it has to be determined. Its determination is accompanied by certain difficulties due to fluid mass quantity, its physical and chemical properties as well as to the form and the law of rigid body velocity change while the body is moving through space filled with fluid.