Why Objects Float or Sink

Q.

Why does an object float or sink when placed on the surface of water?

Q.

Why does a ship made of iron and steel float in water whereas a small piece of iron sinks in it?

Q.

Steel sinks in water but a steel boat floats. Why?

Q.

Why at the highest point, water does not fall out of the bucket when rotated in a vertical circle?

Q.

For transportation of mercury, a container made up of which material is used?

Q.

What is the minimum density of water?

Q. The weight of a body in air is W g and weight in water is X g.find the buoyant force.also find the volume of the object and the buoyant force when dipped in a liquid of 2g/cc.

Q.

In which direction does the buoyant force act on an object immersed in a liquid?

Q.

Give any two effects of a force on a non-rigid body.

Q.

Explain why an iron nail floats on mercury, but it sinks in water.

Q.

A mug full of water appears light as long as it is under water in the bucket than when it is outside water. Why?

Q.

A solid of density $900kg/m^3$ floats in oil as shown in the given diagram. The oil floats on water of density $1000kg/m^3$ as shown. The density of oil in $kg/m^3$ could be :

(a) 850
(b) 900
(c) 950
(d) 1050

Q.

Explain why big boulders can be moved easily by the flood.

Q.

Question 26 (a)

(a) A cube of side 5 cm is immersed in water and then in saturated salt solution. In which case will it experience a greater buoyant force. If each side of the cube is reduced to 4 cm and then immersed in water, what will be the effect on the buoyant force experienced by the cube as compared to the first case for water. Give reason for each case.

Q. An object of mass $100g$ has a volume of $20c{m}^3$. Calculate the density of the object. Also, state whether the object will float or sink in water.

1. $2.0gc{m}^{-3},float$
2. $5.0gc{m}^{-3},sink$
3. $1.0gc{m}^{-3},sink$
4. $5gc{m}^{-3},float$

Q.

How will you determine the density of a cuboidal solid?

Q.

The relative density of a solid is 0.6. It floats water with :

1. whole of its volume inside water

2. 60% volume inside water

3. 60% volume outside water

4. 40% volume inside water floats in water with

Q. What is the C.G.S unit of force? How is it defined?

Q.

When an object is immersed in a fluid, name the two forces acting on it.

Q.

(a) Define buoyant force. Name two factors on which buoyant force depends.
(b) What is the cause of buoyant force ?
(c) When a boat is partially immersed in water, it displaces 600 kg of water. How much is the buoyant force acting on the boat in newtons ? $(g=10m{s}^{-2})$

Q.

If a fresh egg is put into a beaker filled with water, it sinks.On dissolving a lot of salt in the water, the egg begins to rise and then floats.Why ?

Q.

State whether the following statements are true or false :
(a) The buoyant force depends on the nature of object immersed in the liquid.
(b) Archimedes' principle can also be applied to gases.

Q.

Calculate the density of an object of volume $3m^3$ and mass 9 kg. State whether this object will float or sink in water. Give reason for your answer.

Q.

Why do we feel a lot more heavier than before when we come out of a swimming pool

Q.

A cube of side 10 cm completely immersed in water experiences a buoyant force of 1000 N. $(g=10m{s}^{-2})$

1. True

2. False

Q. With increase in temperature of a liquid, the buoyant force acting on a body immersed in it will

1. 
   Increase
2. 
   Decrease
3. 
   Remain same
4. 
   First increase then decrease

Q.

How does the density of material of a body determine whether it will float or sink in water ?

Q.

What is the up thrust experienced by a balloon of volume 120$m^3$ filled with hydrogen. The density of air = 1.140 $\frac{kg}{m^3}$ and density of hydrogen = 0.081$\frac{kg}{m^3}$ at room temperature. What is the maximum weight this balloon can lift?

Q.

The density of a body is $800kg/m^3$. Will it sink or float when dipped in a bucket of water? (Density of water = $1000kg/m^3$).

Q.

_________________ causes acceleration in a body.