Native people all through North and South America employed a bola to hunt for birds and animals. A bola can comprise of three stones, each having mass m, at the ends of three light cords, each having length l. The other ends of the cords are tied altogether to form a Y. The hunter holds one stone and moves to and fro the other two stones over her head. Both stones move altogether in a horizontal circle of radius 2l having speed v0. At a moment if the horizontal component of their velocity is directed in the direction of the quarry, the hunter releases the stone in her hand. As the bola flies via the air, the cords rapidly take a stable arrangement with constant 120 degree angles among them. In the vertical direction, the bola is in free fall. Gravitational forces applied by the Earth make the junction of the cords move with the downward acceleration. You might avoid the vertical motion as you proceed to explain the horizontal motion of the bola.