Tag: archimedes' principle

Quizzes (0) Questions (38)

Questions Related to archimedes' principle

Multiple choice archimedes' principle fluid pressure properties of matter physics

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

  1. molecular theory.

  2. electron theory.

  3. Archimedes' principle.

  4. Bernoulli's principle.
Reveal answer Fill a bubble to check yourself
C Correct answer
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

Multiple choice archimedes' principle fluid pressure properties of matter physics

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:

  1. The ball sinks

  2. The ball rises

  3. The ball remains immersed at its former depth

  4. It oscillates
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The ball floats due to the buoyant force, which depends on the pressure gradient in the fluid. When the air is removed, the pressure at the surface becomes zero, but the pressure gradient (rho*g*h) remains the same as long as the fluid is incompressible; however, if the ball is held up by air pressure or if the surface tension/meniscus changes, it might sink. In standard physics problems of this type, the removal of atmospheric pressure does not change the buoyancy of a submerged object, but if the ball is floating, the lack of air pressure on the top surface while the water pressure remains below causes it to sink deeper.

Multiple choice archimedes' principle fluid pressure properties of matter physics

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

  1. Will go up

  2. Will not change

  3. Will go down

  4. Noe of these
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

Multiple choice archimedes' principle fluid pressure properties of matter physics

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?

  1. $14.7\times 10^3 N$
  2. $1.47\times 10^2 N$
  3. $2.47\times 10^3 N$
  4. $24.7\times 10^2 N$
Reveal answer Fill a bubble to check yourself
C Correct answer
Multiple choice archimedes' principle fluid pressure properties of matter physics

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

  1. Constant acceleration

  2. Decreasing acceleration

  3. Constant velocity

  4. Decreasing velocity
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

As the wooden block rises, the buoyant force remains constant (rho*V*g) while the weight is constant. Since the density of wood is less than water, the net upward force is constant, resulting in constant acceleration.

Multiple choice archimedes' principle fluid pressure properties of matter physics

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

  1. Bernoulli

  2. Archimedes

  3. Boyle

  4. Pascal
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Pascal's law states that pressure applied to an enclosed fluid is transmitted undiminished to every portion of the fluid and to the walls of its container.

Multiple choice archimedes' principle fluid pressure properties of matter physics

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 $\rho _ { \text { water } } = 1000 \mathrm { kg } / \mathrm { m } ^ { 3 } )$

  1. $10 \mathrm { cm }$
  2. $15 \mathrm { cm }$
  3. $20 \mathrm { cm }$
  4. $30 \mathrm { cm }$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When the 200 gm mass is removed, the buoyant force decreases by an amount equal to the weight of 200 gm, which corresponds to the volume of the cube of side L that rises by 2 cm (h = 2 cm). Thus, buoyant force difference = A * h * rho_w * g = 200 gm * g. Solving L * L * 2 cm * (1 g/cm^3) = 200 g gives L^2 = 100 cm^2, so L = 10 cm.

Multiple choice archimedes' principle fluid pressure properties of matter physics

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:

  1. increases

  2. decreases

  3. remains unchanged

  4. insufficient data
Reveal answer Fill a bubble to check yourself
A Correct answer
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.

Multiple choice archimedes' principle fluid pressure properties of matter physics

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:

  1. go up

  2. fall down

  3. remain the same

  4. Can not be decided.
Reveal answer Fill a bubble to check yourself
B Correct answer
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.
Multiple choice archimedes' principle fluid pressure properties of matter physics

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

  1. It floats higher

  2. It stays as before

  3. It sinks

  4. First sinks and then rises
Reveal answer Fill a bubble to check yourself
C Correct answer
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.