Why does a ship made of iron float while a piece of iron of same mass sink in water?
Hello,
Since the ship is designed in such a way that its effective density (m/V) is less than the density of the water.
V = volume of ship
m =mass of ship.
So it floats upon the water. Hence the ship does not sink.
For the nail,
The density of nail (as of iron) is much larger than the water. So it sinks easily.