ИСТИНА

The motion of the celt attracts researchers attention by unusual properties. If we put the celt on a horizontal plane and twist it about its vertical axis, then, after a certain time, it stops rotating about this axis, but vibrations about the other axes may arise and then the celt begins rotating about the vertical axis in the opposite direction. The known studies of the celt motion contain some simplifying assumptions. For example, it is usually assumed that the speed of a contact point with plane is zero (non-holonomic formulation of the problem). In the present paper, it is assumed that at the point of contact of the celt with the plane, in addition to the normal reaction, there is also a force proportional to the velocity of this point of the body and acting in the opposite direction (the viscous friction force).