Advertisements
Advertisements
Question
Explain why an iron needle sinks in water, but a ship made of iron floats on water.
Advertisements
Solution
An iron needle is solid and the density of iron is more than that of water. The weight of the iron needle is more than the buoyant force of water on it, so it sinks in water. Although a ship is made of iron, it has hollow spaces that are filled with air, which makes its average density less than that of water, so the ship floats on water.
APPEARS IN
RELATED QUESTIONS
In which direction does the buoyant force on an object due to a liquid act ?
Why do we feel light on our feet when standing in a swimming pool with water up to our armpits ?
Define the term Density of a substance.
What is a density bottle? How is it used to find the density of a liquid?
A cork piece floats on water surface while an iron nail sinks in it. Explain the reason.
What is the law of floatation?
Define upthrust and state its S.I. unit.
Will a body weigh more in air or vacuum when weighed with a spring balance? Give a reason for your answer.
The mass of a block made of certain material is 13.5 kg and its volume is 15 × 10-3 m3.
(a) Calculate upthrust on the block if it is held fully immersed in water.
(b) Will the block float or sink in water when released? Give a reason for your answer.
(c) What will be the upthrust on block while floating?
Take density of water = 1000 kg m-3.
A block of wood is floating on water with its dimensions 50 cm x 50 cm x 50 cm inside water. Calculate the buoyant force acting on the block. Take g = 9.8 N kg-1.
