Question

The ship made up of iron and steel does not sink in sea water but the same amount of steel and iron in the form of nail or sheet would sink why

Answer 1

the structure of the ship is made such that it contains air chambers in the bottom.

this air increases the buoyancy in the water and make the ship float

Answer 2

It is because ship has large mass and volume is also larger so the density is decreased

But an iron nail has more mass and less volume which increases its density

Thus iron nail sinks in water