Tag: physics

Quizzes (598) Questions (13441)

Questions Related to physics

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

A hydrogen balloon released on the moon would:

  1. climb up with an acceleration of $9.8 \ m/s^2$

  2. climb up with an acceleration of $9.8 \times 6 \ m/s^2$

  3. neither climb nor fall

  4. fall with an acceleration of $9.8/6 \ m/s^2$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

As there is no atmosphere on the surface of the moon  so no bouyancy will act Hence it will fall with acceleration $9.8/6 m/s^2$

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

Statement I:- A block is immersed in a liquid inside a beaker,which is falling freely. Buoyant force acting on block is zero.
Statement II:- In case of freely falling liquid there is no pressure difference between any two points.

  1. Statement I is true,statement II is true and statement II is a correct explanation for statement I.

  2. Statement I is true,Statement II is true and statement II is NOT the correct explanation for statement I.

  3. Statement I is true,Statement II is false.

  4. Statement I is false,Statement II is true.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In a freely falling frame, the effective gravity is zero. Since buoyant force depends on the pressure gradient caused by gravity, the pressure gradient vanishes, making the buoyant force zero.

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

Ice floats on the surface of water because its density is ______ that of water.

  1. more than

  2. less than

  3. same as

  4. cant say
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

TRUE
Ice floats in water because it is less dense than water. So any substance that has a lower density in its solid state than in its liquid state will float.

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

A block of wood floats in water with two-third of its volume submerged. Find the density of wood. Density of water is $10^3\ kg/m^3.$

  1. 0.67

  2. 0.76

  3. 0.82

  4. 0.28
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

For a floating object, the weight of the object equals the weight of the displaced fluid. Thus, density_wood * V_total = density_water * V_submerged. Given V_submerged = (2/3)V_total, the density of wood is (2/3) * 1000 kg/m^3 = 666.7 kg/m^3, which is 0.667 g/cm^3.

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

A body of density $\rho$ sinks in a liquid of denisty $\rho _L$. The densities $\rho$ and $\rho _L$ are related as:

  1. $\rho = \rho _L$

  2. $\rho < \rho _L$

  3. $\rho > \rho _L$

  4. nothing can be said
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

According to archimedes principle a body floats in a fluid if the density of the body is less than that of the fluid.
If the density of body is greater than that of fluid, it will sink.
In the above case, Since the body has  a higher density, therefore it will sink.

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

The hot air balloon rises because it has a gas that is

  1. denser than air

  2. less dense than air

  3. equally dense as air

  4. the given statement is wrong
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Hot air balloon has hot air inside.  Also hot air is less dense than cooler air which surrounds the hot air balloon. This means hot air is lighter than equal volume of cold air.  Hence due to buoyant force of cold air, the balloon rises.

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

If a piece of ice floating on the surface of water in a beaker melts completely, the level of water

  1. Rises

  2. Remains the same

  3. Falls

  4. Initially rises and then falls
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When a piece of ice is placed in a beaker containing water, some of its portion remains out of the water level. Since the volume of ice is greater than the water hence after melting the volume of the piece will decrease and the water level will remain the same.

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

State whether true or false:

Ice is less dense than water (because it has more volume for the same mass), which is why ice floats on water.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Answer is A.

As water is cooled down, however, the molecules have less energy and hydrogen bonding takes over. The molecules form a ordered crystal through hydrogen bonding that spaces the molecules farther apart than when they were in a liquid. This makes ice less dense than water allowing it to float.
Hence, the statement is true.

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

What can you say about the average density of a ship floating on water in relation to the density of water?

  1. Average density of ship is more than the density of water.

  2. Average density of ship is less than the density of water.

  3. Average density of ship is equal to the density of water.

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Average density of ship is less than the density of water.

It is important to realize that, while they are related to it, the principle of flotation and the concept that a submerged object displaces a volume of fluid equal to its own volume are not Archimedes' principle. Archimedes' principle, as stated above, equates the buoyant force to the weight of the fluid displaced.
So, according to law of flotation, a body will float in a fluid if it has less density than the fluid.
So, in order for the ship to float, its average density must be less than the water.

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

Give reasons as to why It is easier to swim in sea water than in river water. 

  1. <span>The density of river water is greater</span>

  2. The density of sea water is greater

  3. Both their densities are the same

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
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