A boy whirls a stone in a horizontal circle of radius 1.3 m and at height 1.6 m above ground level. The string breaks, and the stone flies horizontally and strikes the ground after traveling a horizontal distance of 10 m. What is the magnitude of the centripetal acceleration oA boy whirls a stone in a horizontal circle of radius 1.3 m and at height 1.6 m above ground level. The string breaks, and the stone flies horizontally and strikes the ground after traveling a horizontal distance of 10 m. What is the magnitude of the centripetal acceleration of the stone while in circular motion? the stone while in circular motion?