A ball attached to the end of a string is swung around in a circular path of radius r. if the radius is kept constant and the speed is doubled O the centripetal acceleration remains the same. 0 the centripetal acceleration increases bra factor of 2. O the centripetal acceleration decreases by a factor of 2. G) the centripetal acceleration increases by a factor of 4. O the centripetal acceleration decreases'by a factor of 4