Tag: physics

Questions Related to physics

A hollow metal container floats in water, because it displaces _____ weight of water than/as its own weight.

archimedes' principle fluid pressure properties of matter physics

  1. more

  2. less

  3. same

  4. can't say

Show answer
Correct Option: C
Explanation:

FALSE
If hollow metal container  displaces more weight of water than its own weight it will sink.
Because, we know that by Archimedes principle, the weight of water displaced should be equal to the weight of the part submerged in water. If the weight is greater than the weight of the object, it will sink.

A piece of ice floats in a liquid denser than water.The liquid fills the vessel upto the edge. If ice melts completely then:

archimedes' principle fluid pressure properties of matter physics

  1. water level remains unchanged

  2. water level decreases

  3. water overflows

  4. data is insufficient

Show answer
Correct Option: C
Explanation:

Density of ice is less than that of water. If it melts it becomes water. But still, the density of liquid is greater than water therefore, water remains on top and thus it floats and then overflows.

State whether the given statement is True or False :

When submerged, a $3N$ block appears to weigh only $1N$. The missing weight is equal to the weight of the water.

archimedes' principle fluid pressure properties of matter physics

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Objects weigh more in air than in water. When submerged, the 3 N block appears to weigh only 1 N. The missing weight is equal to the weight of the water displaced. The 2 N weight is equal to the buoyant force.
That is, Loss in weight of body = Weight of water (liquid) displaced by the body = Buoyant force or upthrust exerted by water (any liquid) on the body.

A body of density 5.34  $ \displaystyle g/cm^{3} $ when immersed in water (density 1.0$ \displaystyle g/cm^{3} $ ) will 

archimedes' principle fluid pressure properties of matter physics

  1. float

  2. sink

  3. rise

  4. none of these

Show answer
Correct Option: B
Explanation:

 

Any solid floats on water if its density is less than the density of water(i.e. 1).So, it will sink.

A piece of iron [density 7.6$ \displaystyle gcm^{-3} $] sinks in mercury [density 13.6 $ \displaystyle gcm^{-3} $]. State whether true or false.

archimedes' principle fluid pressure properties of matter physics

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

Since condition for sinking of a body of density $\sigma $ in a liquid of density S is 

                  $\sigma >S.$
& Since iron of density 7.69/cc is less lighter than density of mercury (density 13.6g/cc). Hence iron will float on mercury.

A piece of iron sinks in water but can float in mercury. True or false.

archimedes' principle fluid pressure properties of matter physics

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Conditions for sinking of a body of density $\sigma $ in a liquid of density S is 

           $\sigma \quad >\quad S$
hence iron sink in water & float in mercury as iron is lighter than mercury.

When an object is placed in a liquid whose density is lower than the object, the object will float. True or false.

archimedes' principle fluid pressure properties of matter physics

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

a body of higher density would sink in a liquid of lower density 

so the given object would sink in this case
hence option (B) would be correct.

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

Show answer
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

Show answer
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

Show answer
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.