Advertisements
Advertisements
Question
A plastic cube is released into the water. Will it sink or come to the surface of the water?
Advertisements
Solution
When a plastic cube is released into water, it will come to the surface and float if its density is lower than the density of water. This happens because of buoyancy. Water exerts an upward buoyant force on the cube, and if this force is equal to or greater than the cube’s weight, the cube floats.
In this experiment, the plastic cube floats because it is less dense than water. In contrast, a glass cube usually sinks because its density is greater than that of water, so its weight is greater than the buoyant force acting on it.
RELATED QUESTIONS
What is meant by the term ‘buoyancy’ ?
The density of a body which sinks in water is ......... than 1000 Kg m-3.
The density of brass is 8.4 g cm-3. What do you mean by this statement?
Define the term relative density of a substance.
Distinguish between density and relative density.
Explain the meaning of the statement
‘Relative density of aluminium is 2.7’.
The pressure of water on the ground floor is 40,000 Pa and on the first floor is 10,000 Pa. Find the height of the first floor. (Take : density of water = 1000 kg m-3, g = 10 m s-2)
Two cylindrical vessels fitted with pistons A and B of area of cross-section 8 cm2 and 320 cm2 respectively are joined at their bottom by a tube and they are completely filled with water. When a mass of 4 kg is placed on piston A, Find:
- the pressure on piston A,
- the pressure on piston B, and
- the thrust on piston B.
A body will experience minimum upthrust when it is completely immersed in :
Higher Order Thinking Skill.
How does a fish manage to rise up and move down in water?
