An ice block contains a glass ball. When the ice melts within the water containing vessel, the level of water
Answers
rise.............................
Answer: decrease
Explanation:
When an ice cube with a iron ball inside floating on water melts, the level of water will decrease.
To understand why this is so let us consider the action of the ice and the ball separately.
The ice floats on water because it has lower density than water. When ice is put in water it displace a volume of water which weighs same as the weight of ice. After melting, the volume of ice becomes same as that of the water that it was displacing. Therefore, there is no change in level of water due to melting of ice.
Now let us examine effect of iron ball. The combined density of ice and iron ice is still less than that of water. That is why the ice cube with ball floats. In this case, additional volume of water displaced due to weight of metal piece, weighs same as the weight of ball. This is more than the volume of ball which has higher density than water. When the ice melts, the iron ball no longer is able to float above water and sinks. At this time the the volume of water displaced by the metal piece that has sunk is equal to just the volume of ball. Thus the volume of water displaced by ball reduces on melting of ice. Therefore, the level of water will reduce after melting of ice.
Please note that, if at any time, before complete melting of ice, the ball embedded in ice sinks in the water, temporarily the level of water will rise. The exact amount of rise will depend on the remaining quantity of ice, If only the ball sinks, but the ice cubes remains floating, then also the water level will reduce to the same level as after complete melting of ice.
Hope, that helps