Consider a plane with negligible friction (i.e. treatable as if it were smooth) inclined at an angle with respect to the horizontal. Let A be the bottom of the inclined plane, i.e. the point where it meets the horizontal support surface, and set its height to zero ( ). A mass body is placed on the plane, at height with respect to A, and allowed to slide starting from a standstill. Knowing that when it arrives in A its velocity is equal to , how much is h worth? Use