Problema sentito da Colin Wright: A child, stone in hand, espies a crow on a flagpole. The child throws the stone at the crow. At the moment of loosing the stone the crow flies away, horizontally, at 1 m/s. The stone passes through where the crow had been, and rises one third as high again, before hitting the crow on the way down. Assuming air resistance is negligible, and the child released the stone from the level of the base of the flagpole, what is the horizontal speed of the stone?
