Tag: applications of floatation

Questions Related to applications of floatation

Give reasons as to why It is easier to swim in sea water than in river 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. The density of river water is greater

  2. The density of sea water is greater

  3. Both their densities are the same

  4. None of these

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Correct Option: B
Explanation:

Sea water contains dissolved salts which makes its density more than river water Hence upthrust is more in sea water than river water So it is easier to swim in sea water than in river water 

Give reasons as to why bodies like cork or wood float in 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. They are denser than water

  2. They are less dense than water

  3. They have the same density as that of water

  4. None of these

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Correct Option: B
Explanation:

Density of cork or wood are less than that of water hence they float in water

Give reasons as to why bodies like stones and metals sink in 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. They have higher density compared to water

  2. They have lesser density compared to water

  3. They have the same density as that of water

  4. None of these

Show answer
Correct Option: A
Explanation:

Bodies like stones ans metals sink in water as these substances have density more than that of water

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

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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 %

Show answer
Correct Option: B