The refrigerator has a freezer near its top. This is because the frezeer at the top makes the air near it cool. The cold air being more dense, comes down, while the less dense warm air rises from the lower part. Thus the convection currents formed in a refrigerator keeps the lower part of the refrigerator cool. . . .
The air conditioner are fixed at a certain height. This is because the cold air coming out from the air conditioner is denser and thus moves down. On the other hand, the warm air in the room is less dense and thus moves upwards. Thus, the convection currents formed, keep the room cool. . . .
Whether an object floats or sinks in a liquid depends upon how dense (or heavy) the objects as compared to that liquid.When an object is immersed in a liquid , any of the following three situations can be observed: Object Sinks: If the density of an object is more than that of the liquid, the object will sink. Examples: Iron, aluminium and s . . .
Ice floats on water because the density of ice is less than the density of water. Thus the density of a huge mass of ice, called iceberg is less than that of water , and hence, it floats on water. . . .
The density of sea water is greater than the density of fresh water due to dissolved salts. Thus it is easier to swim in a sea water than in freshwater. . . .