Assertion: In taking into account the fact that any object, which floats, must, have an average density less than that of water, during World War I, a number of cargo vessels are made of concrete.
Reason: Concrete cargo vessels were filled with air.

Assertion: In taking into account the fact that any object which floats must have an average density less than that of water, during World war I , a number of cargo vessels are made of concrete. Reason : Conctere cargo Vessel were filled with air.

Fill in the following blanks with suitable words : (a ) Force acting on a units area is called …….. (b) It is the …..force which makes objects appear lighter in water (c ) A heavy ship floats in water because its ………….density is less than that of water . (d ) In fluids (liquids and gases ), pressure acts in .........direction ,and pressure .....as the depth increases, (e ) In order to sink in fluid ,the density of an object must be .........than the ...... of the fluid . (f ) snow shoes work by spreding out a preson's ........over a much bigger ..........