You are in a boat with a rock on a fresh-water lake You throw the rock into the lake With respect to the land what happens to the level of the water in the lake goes up goes down stays the same?

the level with relative to the shore will decrease. This is because when the rock is on the boat, the weight of the rock is added to that of the boat and the volume of the boat displaces the water, causing it to sink in and thus raising the level of water. Once the rock is thrown out, the boat gets lighter and hence exerts a less pressure. Also as the volume of the rock is less than the boat, the pressure exerted by rock and boat seperately is less than exerted by them together...hence the level decreases...