Tag: archimedes' principle

Questions Related to archimedes' principle

Apparent loss of weight of a body when immersed in a liquid can be explained on the basis of 

archimedes' principle fluid pressure properties of matter physics

  1. molecular theory.

  2. electron theory.

  3. Archimedes' principle.

  4. Bernoulli's principle.

Show answer
Correct Option: C
Explanation:

Archimedes principle states that  loss in weight of a partially or fully immersed body in a fluid is equal to the weight of the fluid displaced .

so , option (C) is correct

A ball floats on the surface of water in a container exposed to the atmosphere. Will the ball remain immersed at its former depth or will it sink or rise if the container is covered and the air is removed:

archimedes' principle fluid pressure properties of matter physics

  1. The ball sinks

  2. The ball rises

  3. The ball remains immersed at its former depth

  4. It oscillates

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Correct Option: A

A piece of ice is floating on water in a container. What will happen to the surface of the water when whole ice piece melts

archimedes' principle fluid pressure properties of matter physics

  1. Will go up

  2. Will not change

  3. Will go down

  4. Noe of these

Show answer
Correct Option: B
Explanation:
The water level eill not change. As the mass of ice before and after melting will remain same. When the ice was floating, the volume of water displaced has the mass equal to that of ice. After melting, that mass of ice has been converted into water. 
Thus there is no net change in level.

In a car lift compressed air exert a force F1 on a small Piston having radius of 5 cm. This pressure is transmitted to second piston of radius 15 cm. If the mass of the car to be lifted is 1350 kg. What is F1?

archimedes' principle fluid pressure properties of matter physics

  1. $14.7\times 10^3 N$

  2. $1.47\times  10^2 N$

  3. $2.47\times  10^3 N$

  4. $24.7\times 10^2 N$

Show answer
Correct Option: C

A wooden block is taken to the bottom of a lake of water and then released . it rise up with a 

archimedes' principle fluid pressure properties of matter physics

  1. Constant acceleration

  2. Decreasing acceleration

  3. Constant velocity

  4. Decreasing velocity

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Correct Option: A

Pressure applied to an enclosed fluid is transmitted undiminished to every portion of the fluid and the walls of the containing vessel. This law was first formulated by

archimedes' principle fluid pressure properties of matter physics

  1. Bernoulli

  2. Archimedes

  3. Boyle

  4. Pascal

Show answer
Correct Option: A

A cube of wood supporting $200 \mathrm { gm }$ mass just floats in water in fully submerged state. When the mass is removed cube rises by $2 \mathrm { cm }$ above water level. Find the size of cube? (take $\rho _ { \text { water } } = 1000 \mathrm { kg } / \mathrm { m } ^ { 3 } )$

archimedes' principle fluid pressure properties of matter physics

  1. $10 \mathrm { cm }$

  2. $15 \mathrm { cm }$

  3. $20 \mathrm { cm }$

  4. $30 \mathrm { cm }$

Show answer
Correct Option: C

A piece of ice is floating in a beaker containing thick sugar solution of water. As the ice melts, the total level of the liquid:

archimedes' principle fluid pressure properties of matter physics

  1. increases

  2. decreases

  3. remains unchanged

  4. insufficient data

Show answer
Correct Option: A
Explanation:

Let $\rho $=density of sugar solution $> \rho _{w}$
m=mass of ice.
In floating condition weight=upthrust
$\therefore $   $mg=V _{I}\rho g$
or $\displaystyle V _{I}=\frac{m}{\rho }$          (i)
When ice melts, m mass of ice becomes m mass of water. Volume of this water formed.
$\displaystyle V _{F}=\frac{m}{\rho _{w}}$          (ii)
Since $\rho _{w}< \rho $, $V _{F}> V _{I}$. Hence level will increase.

A boat full of scrap iron is floating on water in a lake. If all the iron is dropped into the water, the level of water will:

archimedes' principle fluid pressure properties of matter physics

  1. go up

  2. fall down

  3. remain the same

  4. Can not be decided.

Show answer
Correct Option: B
Explanation:
According to Archimedes' principle, any body completely or partially submerged in a fluid at rest is acted upon by an upward, or buoyant force,the magnitude of which is equal to the weight of the fluid displaced by the body
As boat filled with scrap iron is floating on lake, buoyant force acting on boat is more than its weight.
                                              $F _b > W _b + W _{fe}$
since,                                    $W _b<W _b +W _{fe}$
therefore,level of water will fall down across the boat.

If a piece of wood just floats in water. What happens to it in ethanol?

archimedes' principle fluid pressure properties of matter physics

  1. It floats higher

  2. It stays as before

  3. It sinks

  4. First sinks and then rises

Show answer
Correct Option: C
Explanation:

At room temperature and standard pressure, the first family of alcohol (methanol, ETHANOL and iso-propyl) all have densities of about 0.79g/cc compare to water at the same conditions with a density of 1.0g/cc.

Since the density of ethanol is less than the density of water so, when a piece of wood which is just floating in water is placed in ethanol, sinks.