A block of mass 0.23 kg slides down a frictionless track with the shape shown above. The circular portion of the track has a radius 0.

A block of mass 0.23 kg slides down a frictionless track with the shape shown above. The circular portion of the track has a radius 0.55 m. Find the minimum vertical height above the ground from which the block is released at rest so that it flies off the ramp just when it reaches the circular portion of the track.