Tag: upthrust in fluids, archimedes' principle and floatation

Questions Related to upthrust in fluids, archimedes' principle and floatation

A hot air balloon rises because it is filled with a gas :

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

  1. denser than air

  2. less dense than air

  3. as dense as air

  4. the given statement is wrong

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Correct Option: B
Explanation:

More denser objects stays at the bottom.

Since, the hot air balloon rises because it is filled with a gas which is less dense than the air .So, the air has the tendency to move down and the balloon has the tendency to move in the upward direction.

What happens when an object having density less than that of water is immersed in it?

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

  1. It sinks

  2. It floats

  3. Unsure

  4. May sink or float

Show answer
Correct Option: B
Explanation:

the buoyant force depends on the density of liquid. When the density of the object is less than that of the liquid, it floats on the liquid because the upthrust or buoyant force of water is more than the gravity acting on the object.

If the weight of the body immersed in the liquid is equal to the force of buoyancy acting on it, then the body will

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

  1. Float above the liquid surface

  2. Float just inside the liquid surface.

  3. Sink

  4. None

Show answer
Correct Option: B
Explanation:

If the weight of the body immersed in the liquid is equal to the force of buoyancy acting on it, then the body will float just inside the liquid surface.

A piece of ice is floating in a jar containing water. When ice melts, the temperature of water falls from $4^0C$ to $1^0C$. The level of water :

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

  1. rises

  2. falls

  3. remains unchanged

  4. changes erratically

Show answer
Correct Option: C
Explanation:

Remains unchanged because there is no change in mass.

The correct option is C.

A steel wire of length 1 m and cross-sectional area $1.5 mm^2$ is hung from. rigid support, with a stone of volume 2000 cm^3 hanging from the other end. Find the decrease in the length of the wire, when the stone is completely immersed in water. (Ysteel = $210^11 Nm^-2$, $\rho$ water = $103 kgm^-3$)

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

  1. 0.06533 mm

  2. 0.02533 mm

  3. 0.04533 mm

  4. 0.011533 mm

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Correct Option: C

A cubical block of iron of side $5cm$ is floating in mercury taken in a vessel. What is the height of the block above mercury level. $(\rho _{Hg}=13.6g/cm^3 ,\rho _{fe}=7.2 g/cm^3)$

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

  1. $3.65cm$

  2. $3.35cm$

  3. $2.65cm$

  4. $2.35cm$

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Correct Option: C

An ice berg is floating in sea water. The density of ice is $ 0.92\, gm\,cm^{-3}$ and that of sea water is $ 1.03\,gm\,cm^{-3}$. The  percentage of ice berg below surface of water 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. 3 %

  2. 11 %

  3. 89 %

  4. 92 %

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Correct Option: B

A person of mass $m$ is standing on one end of a plank of mass $M$ and length $L$ and floating in water. The person moves from one end to another and stops. The displacement of the plank 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. $\dfrac {Lm}{(m+M)}$

  2. $Lm(M+m)$

  3. $\dfrac {(m+M)}{Lm}$

  4. $\dfrac {LM}{(m+M)}$

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Correct Option: A

A cube of 3 side L floats in a liquid of density 3 times the density of cube. What length of the cube will out side the liquid?

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

  1. $\dfrac{L}{3}$

  2. $\dfrac{2L}{3}$

  3. $\dfrac{2L}{5}$

  4. $\dfrac{L}{5}$

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Correct Option: C

A wire of length L M made 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 millimetre which it can continue to floaters

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

Show answer
Correct Option: C