A ball suspended on a thread of length l lies on the surface of a smooth sphere of radius R. The distance from the point of suspension to the center of the sphere is equal to d (figure). Calculate the tension of the thread and the reaction of the sphere for a stationary ball. Determine the speed v that must be imparted to the ball in the direction perpendicular to the plane of the drawing so that the reaction of the sphere becomes equal to zero. Consider the ball to be a point ball. The thread is weightless and inextensible.

Answer. Format gif