Why Objects Float or Sink

Q.

Define buoyancy.

Q.

The vessel shown in the figure has two sections of areas of cross-section $A_1$ and $A_2$. A liquid of density p fills both the sections, up to a height h in each.

Neglect atmospheric pressure.

1) The pressure by the liquid on the base of the vessel is 2h pg

2) The force exerted by the liquid on the base of the vessel is 2h pg$A_2$

1. Only two is correct

2. 1 and 2 are correct

3. Only one is correct

4. All are correct

Q. A piece of pure gold of density $(d_1=9.300g/{cm}^3)$ is suspected to be hollow inside. It weighs $38.250g$ in the air and $33.865g$ in water. Calculate the volume of the hollow portion in the gold if any.

Q.

What is mean by buoyancy and buoyant force?

Q. Question 20
Why does a block of plastic released under water come up to the surface of water?

Q.

A bunch of balloons with a sandbag of mass $m$ attached with a string is rising with an acceleration $a$. A fraction of sand is dropped from it, the acceleration of balloon will ___ .

1. decrease

2. remain the same

3. increase

4. none of these

Q. A block of ice of density $0.9gmc{c}^{-1}$ and of volume $100cc$ floats in water. Then volume of ice inside the water

1. $90cc$
2. $50cc$
3. $9cc$
4. $10cc$

Q. Which of the following conditions is true for a sinking body?

1. Weight of the displaced liquid > Weight of the body
2. Buoyancy = Weight of the body
3. Buoyancy > Weight of the body
4. Weight of the displaced liquid < Weight of the body

Q.

A body floats or sinks due to difference in their:

1. Densities

2. Pressures

3. Masses

4. None of these

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