# Buoyant Force

## Trending Questions

**Q.**

For a floating body, how is its weight related to the buoyant force?

**Q.**

The magnitude of buoyant force on a body of fixed volume when submerged completely depends on

Density of liquid

Density of body

Weight of body

None of these

**Q.**

Name the two factors that affect the buoyant force.

**Q.**

The fundamental frequency of a sonometer wire is $n$. If the length and diameter of the wire are doubled keeping the tension the same, then the new fundamental frequency is

$\frac{2n}{\sqrt{2}}$

$\frac{n}{2\sqrt{2}}$

$\sqrt{2}n$

$\frac{n}{4}$

**Q.**A body floats with 2/5 th of its volume above the surface of water. Calculate the density of the material of the body in gcm

^{gcm-3}

**Q.**

Define Floating.

**Q.**

Explain why it is easier to lift a stone under water than in air.

**Q.**

It is easy to pull the bucket as long as it is inside water, but as soon as it starts coming out of the water, it appears to become heavy because of

upthrust

the change in density of the bucket in water.

the surface tension of water.

the viscosity of water.

**Q.**

How is the bouyant force related to the density of liquid

**Q.**

A body immersed in a liquid appears lighter than it really is. Explain.

**Q.**

While drawing water from a well with a bucket the bucket of water appears to be lighter when it's under water is than when it's out of it . Give reason

**Q.**A cork is floating on the surface of water. The buoyant force acts in the

- upward
- downward
- parallel

**Q.**

A solid weighs 50 N in the air and 45 N when completely immersed in water. Density of water ρ = 1000 kg/m3. Calculate the volume of the solid.

(Take acceleration due to gravity = 10 m/s2)

**Q.**

A piece of sealing wax weighs $0.27kgf$ in air and $0.12kgf$ when immersed in water. Calculate its:

- relative density, and
- apparent weight in a liquid of density $800kg/{m}^{3}$

**Q.**The upward force acting on an object submerged in a liquid is called:

- Buoyant force
- Magnetic force
- Gravitational force
- Frictional force

**Q.**

A stone of density 3000 kg/m^{3} is lying submerged in water of density 1000 kg/m^{3}, if the mass of stone in air is 150 Kg, calculate the force required to lift the stone. Take g = 10 m/s^{2}

**Q.**

A bucket of water of $50kg$ is raised from a depth of $100m$ to the ground by a rope. The mass of the rope is $1kg$ per meter what is the work done?

**Q.**

Describe an activity to verify the Archimedes' principle.

**Q.**

Write three phenomena which can be explained with the help of Newtons law of gravitation.

**Q.**Buoyant force is an upward force that is equal to the weight of the fluid it

- displaces
- generates
- overcomes
- holds

**Q.**

A block of silver displaces 200 ml of water in a measuring cylinder. If the density of silver is 10300 kg/m3, find the mass of block.

**Q.**

When an object is immersed in a fluid, which of the following forces will act on the object?

Gravitational force

Buoyant force

Both A and B

Frictional force

**Q.**

What happens to the weight of a body when it is immersed in a liquid.

Remains the same.

It will decrease.

It will increase.

It will increase first and then decrease.

**Q.**

A body experiences the same buoyant force when it floats and sinks in water.

True

False

**Q.**

Because buoyant force act in a direction opposite the force of gravity the net force acting on an object submerged in a fluid such as water is smaller than the objects weight.

- True
- False

**Q.**

Differentiate between flotation and sinking.

**Q.**

The value of G (gravitational constant) depends upon____

The mass of the two bodies

The distance beween the two bodies

none of these

the medium between 2 bodies

**Q.**

A sphere of iron and a block of wood having the same volume are held under water. Which of these will experience a greater buoyant force?

- Wooden block
- Iron sphere
- Both A and B
- Can’t be determined

**Q.**

A body of mass m is immersed in water with 3/4th of volume outside of water. Buoyant force acting on it is 1000N. Total volume of body is

( Take density of water as 1000kg/m3 and accelaration due to gravity as 10m/s2)

1m3

0.8m3

10m3

0.4m3

**Q.**

A body would experience greater buoyant force in a liquid whose density is (assume that the body is fully submerged)

$5g/c{m}^{3}$

$1000Kg/{m}^{3}$

$13.6g/c{m}^{3}$

$800g/c{m}^{3}$