Question

A cubical block is floating in a liquid with one fourth of its volume immersed in the liquid if whole of the system accelerates upwards with acceleration G/4 the fraction of volume immersed in the liquid will be

Answer 1

The fraction of volume immersed in the liquid will be same as before i.e 1/2.

Fraction of volume immersed in the liquid  

Vin=(ρ/σ)V

i.e. it depends upon the densities of the block and liquid. So there will be no change in it if system moves upward or downward with constant velocity or some acceleration .

Answer 2

According to the Archimedes principle,

When body floats over the liquid,

Weight of the body=upthrust

Weight of the body is define as=Vρg

where V is the volume of the body and ρ is the density of the liquid,

upthrust=V1σg

where V1 is the volume of the liquid displaced and σ is the density of the liquid

Vρg=V 1σg

Vρ=V1σ

So volume of the body in liquid only depends on the densities of the two. It will not get affected when system moves upward or downward.

Hence volume in liquid will remain one fourth i.e. 1/4

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