Tag: archimedes' principle

Questions Related to archimedes' principle

A body having density less than 1 $ \displaystyle gcm^{-3} $ floats in water. True or false

archimedes' principle fluid pressure properties of matter physics

  1. True

  2. False

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Correct Option: A
Explanation:

Conditions of a body of density $\sigma $ to float in liquid of density S is 

         $\sigma \quad \le \quad S$
hence a body of density 1gm/cc will float in water.

why does an iron rod sink in water?

archimedes' principle fluid pressure properties of matter physics

  1. The density of rod is more than that of water

  2. The volume of water is more than the weight of the object

  3. Both A and B

  4. None of the above

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Correct Option: A
Explanation:

The buoyant force depends on the density of liquid. When the density of the object is more than the density of the liquid, it sinks because the gravitational force acting on the object is more than the buoyant force of water.

State whether True or False.

Objects that sink will always displace their volume. 

archimedes' principle fluid pressure properties of matter physics

  1. True

  2. False

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Correct Option: A
Explanation:

Objects that sink will always displace the same volume of water as that of body which gives the net buoyant force applied on the body.

A body of mass 400 g has a volume of 300 cm$^3$. Will body sink in water or not? [Density of water = 1000 kg/m$^3$]

archimedes' principle fluid pressure properties of matter physics

  1. Sink

  2. Float

  3. Sink partly

  4. Float partly

Show answer
Correct Option: A
Explanation:
Given :     Density of water     $\rho _w = 1000$ $kg/m^3  = 1$ $g/(cm)^3$
Density of body        $\rho _s = \dfrac{M}{V} = \dfrac{400}{300} = 1.33$  $g/(cm)^2$
$\implies$     $\rho _s >\rho _w$
Thus the body will sink in water.

A slid floats in a liquid in a partially dipped position.

archimedes' principle fluid pressure properties of matter physics

  1. The solid exerts a force equal to its weight on the liquid

  2. The weight of the displaced liquid equals the weight of the solid

  3. The liquid exerts a force of buoyancy on the solid which is equal to the weight of the solid

  4. The weight of the dipped part of the solid is equal to the weight of the displaced liquid

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Correct Option: A,B,C
Explanation:

The force that solid exerts on liquid is its weight. Hence option A is correct.
Since the solid is stationary, the weight of solid is equal to the force exerted on it by liquid.
According to Archimedes' Principle, the buoyant force acting upwards on the solid is equal to the weight of the liquid displaced. Hence option B and C are correct.

A balloon lifting in air follows:

archimedes' principle fluid pressure properties of matter physics

  1. Law of gravitation

  2. Archimedes principle

  3. Laws of motion

  4. all of the above

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Correct Option: D
Explanation:

In a lifting balloon, force of gravitation acts downwards as on all other materials present on the earth, given by $mg$.

Also Archimedes' principle acts on the balloon to provide a buoyant force $V\rho g$ upwards, and greater in magnitude than the gravitational force downwards. (Where $\rho$ is the density of air)
Hence Newton's law of motion provides the acceleration of the balloon upwards, given by: $ma=V\rho g-mg$

When a body is wholly or partly immersed in a liquid it experiences. 

archimedes' principle fluid pressure properties of matter physics

  1. An up-thrust or down-thrust depending on the density of the liquid

  2. An up-thrust

  3. A down-thrust

  4. None of the above

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Correct Option: B
Explanation:

Whenever a body is wholly or partially immersed in a liquid it experience an upthrust or buoyant force.

The principle on which Hare's apparatus works on is.

archimedes' principle fluid pressure properties of matter physics

  1. Bernoulli's principle

  2. Archimedes principle

  3. Newton's law

  4. Kepler's law

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Correct Option: B
Explanation:

Hare`s apparatus is used  to compare the densities of two liquids and is base on Archimedes principle .

so option (B) is correct

The upward thrust exerted on the body by the liquid acts vertically upwards through the center of gravity of the displaced liquid.

archimedes' principle fluid pressure properties of matter physics

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

when a body is immersed in a fluid an downward force mg acts on it and to balance this force an upward force kown by the name buoyant force is exerted by the fluid .

so given statement is true , hence option ( A) is correct

A body is floating in a given liquid with half of its volume above the surface of the given liquid. If the body is slightly pushed into the liquid, then the body,

archimedes' principle fluid pressure properties of matter physics

  1. sinks in the liquid and settles at the bottom.

  2. come back to its position after some time.

  3. keeps oscillating in vertical direction.

  4. it jumps into the air and falls on the liquid.

Show answer
Correct Option: B
Explanation:

Before pushing body was in the position of equilibrium so if we disturbs the eqm than with the passage of time it would come back to its eqm position .

so option (B) is correct