“…If the initial values of the angular and linear (sliding) velocities are nonzero, it is difficult to reach any analytic simplifications. In our paper [20], the system of equations ( 6) was solved in the (ξ, η) coordinate system, but with this approach the accuracy of results was not satisfied enough. Furthermore, at most final points the method tends to oscillate significantly, because near β = β * , a situation with a singularity may appear.…”