Tag: applications of floatation

Questions Related to applications of floatation

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

physics upthrust in fluids, archimedes' principle and floatation applications of floatation principle of floatation and its applications when do objects float on water?

  1. $ 0.6 g/cm^3 $

  2. $ 1.6 g/cm^3 $

  3. $ 2.5 g/cm^3 $

  4. $ 3.6 g / cm^3 $

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Correct Option: C

A block of wood floats in a liquid with four-fifths of its volume submerged. If the relative density of wood is $0.8$, what is the density of the liquid in units of $kg\, m^{-3}$?

physics upthrust in fluids, archimedes' principle and floatation applications of floatation principle of floatation and its applications when do objects float on water?

  1. $750$

  2. $1000$

  3. $1250$

  4. $1500$

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Correct Option: C

We have two different liquids A and B whose relative densities are 0.75 and 1.0, respectively. If we dip solid objects P and Q having relative densities 0.6 and 0.9 in these liquids, then:

physics upthrust in fluids, archimedes' principle and floatation applications of floatation principle of floatation and its applications when do objects float on water?

  1. P floats in A and Q sinks in B

  2. P sinks in A and Q floats in B

  3. P floats in B and Q sinks in A

  4. P sinks in B and Q floats in A

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Correct Option: C
Explanation:

If solid object has higher density than liquid then it will sink in that liquid otherwise it will float.
R.D. of liquid A = 0.75
R.D. of liquid B = 1.0
R.D. of object P = 0.6
R.D. of object Q = 0.9

  • P has R.D. less then both the liquids. so it will float in both the liquids.
  • Q has R.D. more than liquid A, so it will sink in A.
  • Q has R.D. less than liquid B, so it will float in B.

A metallic wire of length, "l" is lying horizontally on the surface of liquid of density $ '\rho' $ The maximum radius of wire so that it may not sink will be

physics upthrust in fluids, archimedes' principle and floatation applications of floatation principle of floatation and its applications when do objects float on water?

  1. $ \sqrt { \frac { 2T }{ \pi \rho g } } $

  2. $ \sqrt { \frac { T }{ \pi \rho g } } $

  3. $ \sqrt { \frac { 2T }{ \rho g } } $

  4. $ \sqrt { \frac { T }{ \rho g } } $

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Correct Option: B

A cube of wood supporting a $200$ gm mass just floats in water. When the mass is removed the cube rises $2$ cm at equilibrium. Find size of the cube.

physics upthrust in fluids, archimedes' principle and floatation applications of floatation principle of floatation and its applications when do objects float on water?

  1. 10cm

  2. 12cm

  3. 15cm

  4. 4cm

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Correct Option: A

A cubical box of wood of side $30\, cm$ weighing $21.6\, kg$ floats on water with two faces horizontal. The depth of immersion of box is :

physics upthrust in fluids, archimedes' principle and floatation applications of floatation principle of floatation and its applications when do objects float on water?

  1. $30\, cm$

  2. $12\, cm$

  3. $6\, cm$

  4. $24\, cm$

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Correct Option: C

A wire of length $L$ metrs, made of a material of specific gravity $8$ is floating horizontally on the surface of water. If it is not wet by water, the maximum diameter of the wire (in mm) up to which it can continue to float is (surface tension of water is) ($T=70\times 10^{-3} \ N/m$)

physics upthrust in fluids, archimedes' principle and floatation applications of floatation principle of floatation and its applications when do objects float on water?

  1. $1.5$

  2. $1.1$

  3. $0.75$

  4. $0.55$

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Correct Option: A

A hollow cylinder of copper of length $25\, cm$ and area of cross-section $15\, cm^2$, floats in water with $3/5$ of its length inside water. Then 

physics upthrust in fluids, archimedes' principle and floatation applications of floatation principle of floatation and its applications when do objects float on water?

  1. Apparent density of hollow copper cylinder is $0.6\, gcm^{-3}$

  2. Weight of the cylinder is $225\, gf$

  3. Extra force required to completely submerge it in water is $150\, gf$

  4. Extra force required to completely submerge it in water is $225\, gf$

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Correct Option: B

Two solids $A$ and $B$ float in water. It is observed that $A$ floats with half its volume immersed and $B$ floats with $\dfrac{2}{3}$ of its volume immersed. Compare the densities of A and B.

physics upthrust in fluids, archimedes' principle and floatation applications of floatation principle of floatation and its applications when do objects float on water?

  1. $4:3$

  2. $2:3$

  3. $3:4$

  4. $1:3$

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Correct Option: C

The weight of the liquid displacement by a body when the body is immersed in it is called 

physics upthrust in fluids, archimedes' principle and floatation applications of floatation principle of floatation and its applications when do objects float on water?

  1. Apparent weight

  2. Upthrust

  3. Lateral pressure

  4. Relative density of body

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Correct Option: A