Tag: principle of floatation and its applications

Questions Related to principle of floatation and its applications

A wooden cylinder floats vertically in water with half of its length immersed, Density of wood is

  1. Equal to that of water

  2. Half the density of water

  3. Double the density of water

  4. One fourth the density of water


Correct Option: C

A wooden cube floats in water partially immersed. When 200 g weight is put on the cube, it further immersed by 2 cm. The length of the side of the cube is

  1. $1.0 cm$

  2. $\sqrt{10}cm$

  3. $10 cm$

  4. $20 cm$


Correct Option: C

A ball weighing  $4 kg$  of density  $4000{ kg }\quad { m }^{ { -3 } }$  is completely immersed in water of density  $1000{ kg }\quad { m }^{ { -3 } }.$  Find the force of buoyancy on it. (Given $g = 10 { ms } ^ { - 2 }$)

  1. $100{ N }$

  2. $1{ N }$

  3. $20{ N }$

  4. $10{ N }$


Correct Option: D

A ship of mass $ 3 \times10$ initially at rest is pulled by a force of $5\times 10$ N  through a distance of  Assuming that the resistance due to water is negligible, the speed of the ship is 

  1. 1.5 m/s

  2. 68 m/s

  3. 0.1 m/s

  4. 5 m/s


Correct Option: C

A balloon has volume of $1500\, m^3$. It is filled with hydrogen $(\rho = 0.09\, gL^{-1})$. If the density of air is $1.29\, gL^{-1}$, it can lift a total weight of 

  1. $2400\, kg$

  2. $1600\, kg$

  3. $2700\, kg$

  4. $1800\, kg$


Correct Option: C

An object measuring $2\times 2\times 5{cm}^{3}$ has a mass of $16g$. It is put in water of density $1g/cc$. Percentage of its volume outside water while floating is

  1. $10$%

  2. $20$%

  3. $30$%

  4. $40$%


Correct Option: C

lce pieces are floating in a beaker  $A$  containing water and also in a beaker  $B$  containing miscible liquid of specific gravity  $1.2 .$  When ice melts, the level of

  1. Water increases in $A$

  2. Water decreases in $A$

  3. Liquid in $B$ decreases

  4. Liquid in $B$ increases


Correct Option: C

Statement I:- An ice ball is floating in water. Some stone pieces are embedded inside the ice. When ice will melt level of water will fall.
Statement I:- In floating condition,stone pieces will displace more liquid compared to the condition when they sink.

  1. Statement I is true,statement II is true and statement II is a correct explanation for statement I.

  2. Statement I is true,statement II is true and statement II is NOT the correct explanation for statement I.

  3. Statement I is true,Statement II is false.

  4. Statement I is false,Statement II is true.


Correct Option: A

A block of wood is floating in water in a closed vessel as shown in the figure. The vessel is connected to an air pump. When more air is pushed into the vessel, the block of wood floats with : (neglect compressibility of water)

  1. Larger part in the water

  2. Smaller part in the water

  3. Same part in the water

  4. At some instant it will sink


Correct Option: C

A block of wood floats is water with $ 2/5^{th} $ of its volume above the surface Calculate the density of wood.

  1. $ 0.6 g/cm^3 $

  2. $ 1.6 g/cm^3 $

  3. $ 2.5 g/cm^3 $

  4. $ 3.6 g / cm^3 $


Correct Option: C