Question

A stone is flying off tangendtially when we stops rolling or rotating. WHY ???

Answer 1

Let's take a boy rotating a stone connected to a string. ( he holds the string). When he rotates it, there are two forces acting on the stone, one is tangentially outwards and another is radially towards the centre (centripetal). The centripetal force stops it from going tangentially outwards and instead makes it traverse a circular path. When the rotation is stopped, the stone loses the centripetal force, and so due to the tangential force, the stone goes in a path tangential to the circle.