loaded test tube placed in pure milk sinks to a certain mark (M). Now some water is mixed with the milk. Will the test tube sink more or less? Explain.
A Piece of ice is placed gently on the surface of water in a glass so that when ice floats, the water comes up to the brim of the glass. what will happen to the level of water when the ice melts? will it overflow? (2) in the above case what will happen if instead of water the glass is filled with (a) with a liquid denser than water. (b) a liquid lighter than water.
(a) Whether an object sinks or floats depends upon the its density and the density of the liquid its placed inside of. If the density of the liquid is more than the object it will float and vice versa. The density of milk-water mixture is less compared to only milk. The density difference between the two (liquid and object) has now changed. This would lead the test tube to sink deeper than before.
(b) If the ice is placed in water it will float as the density of ice is less when compared. This is because same the mass, ice has a larger volume. If the ice melts it will turn into water and the volume of the combined water would now be less than the before, this is because
volume of water + ice > volume of water + volume of ice turned into water
SO, water not overflow if the ice was completely immersed in water before melting.
If use an other liquid...
if the density of the liquid is more than water than the ice will float, like before.
if the density of the liquid is less than water than the ice will sink to the bottom.