Same chapter3 marksDifficulty: Medium
Why is it easier to swim in sea water than in river water?
Fluids
3 marksDifficulty: Medium
Why does a ship float although it is made of iron, which is denser than water?
Original Khojo Papers practice question — not from a past board paper.
Answer
A ship is hollow, so the volume of water it displaces is far greater than the volume of the iron in it, and its average density is much less than that of water. It sinks until the weight of the water displaced equals its own weight, which is the law of flotation.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
If the hull is breached and water fills it, the average density rises and the ship sinks.
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