When an object is placed on a liquid, its weight  depresses the surface, and if surface tension and downward force become equal then  it is balanced by the surface tension forces on either side , which are each parallel to the waters surface at the points where it contacts the object. Notice that small movement in the body may cause the object to sink. As the angle of contact decreases, surface tension decreases. The horizontal components of the two  arrows point in opposite directions, so they cancel each other, but the vertical components point in the same direction and therefore add up to balance . The objects surface must not be wettable for this to happen, and its weight must be low enough for the surface tension to support it. If  denotes the mass of the needle and  acceleration due to gravity, we have