Mechanical properties of fluids

The water level rises in the vessel because the reason is floatation and density of the ice and water relativity. The ice cube with ball floats. In this case, an additional volume of water displaced due to the weight of the metal piece weighs the same as the weight of the ball. This is more than the volume of a ball which has a higher density than water before completing the melting of ice, the ball embedded in ice sinks in the water, temporary the level of water will rise.