The boy in the figure here is initially seated on the top of a hemispherical ice mound of radius R = 13. He begins to slide down the ice, with a…

The boy in the figure here is initially seated on the top of a hemispherical ice mound of radius R = 13.3 m. He begins to slide down the ice, with a negligible initial speed. Approximate the ice as being frictionless. At what height does the boy lose contact with the ice?