Solution V81 D3, reshebnik termehu Targ SM 1982

Solution of the D3 version 81 of Reshebnik on theoretical mechanics manuals SM Targ 1982.
CONDITION TO THE PROBLEM D3 (p. 58-61 in the training manual Targ SM 1982.):
Thin smooth rod located in the vertical plane, is bent so that the straight portion comprises two circular arcs of radius R = 0,5 m, r = 0,6R, conjugate at point K (Fig. D3.0-D3.9, Table. DZ). Strung on the rod weight P ball attached to a spring with a stiffness coefficient c = k (P / R); the other end of the spring is fixed at O. length of the spring in the state is nedeformirovapnom l0.
The ball starts to move without the initial velocity of the B0 position determined by an angle α (with α = 90 ° ball count just shifted from the equilibrium position toward the point B1); reaching the B1 point, shown in the figure, the ball is released from the spring and then moves only under the influence of gravity.
Considering balloon material point, to determine what speed it will be coming in the point D, the force with which will put pressure on the rod at this point (force pressure P expressed in terms of the weight of the ball). The position of point D, when it is located on an arc of radius R, defined by the angle β, and the arc radius of r-angle γ. Fig. 2 and 3 of an arbitrary point of the arc B1 ED.
Task D3 - the application of the theorem of change of kinetic energy terms.