June 14, 2020
equilibrium stability; common center of gravity; optimal bending; critical angles, stability coefficient, force of gravity, external force, overturning
This paper combines two previous scientific works [1, 2]. It investigates conditions of the equilibrium stability of a cylinder (shaped homogeneous body) in order to study the equilibrium stability of a human body of different proportions. A new method to determine a human body’s common centre of gravity is proposed. An optimal bending forward angle at which the degree of the equilibrium stability of an upright standing person reaches its maximum value is defined and relevant conclusions are drawn. In addition, external forces are also introduced, which may disturb the stable equilibrium and cause the body to tumble. The paper also introduces the concept of the coefficient of the stable equilibrium and proposes a formula for its calculation. Finally, a formula is set up to obtain the maximum value of external forces under which the body still maintains the state of equilibrium.