Large sphere was built, with a radius of about 5. imagine that such a sphere has a radius "r" and a frictionless surface. a small block of mass "m" slides starts from rest at the very top of the sphere and slides along the surface of the sphere. the block leaves the surface of the sphere when it reaches a height "h(critical)" above the ground. using newton's 2nd law, find v(critical), the speed of the block at the critical moment when the block leaves the surface of the sphere. assume that the height at which the block leaves the surface of the sphere is h(critical). express the speed in terms of r, h(critical), and g (the magnitude of the accleration due to gravity). do not use (theta) in your answer.