Question

A block (less dense than water) weighs 25g in air. A denser object is attached to the block and is suspended from the block. The combined system is again weighed. It weighs 110 g when the block is completely outside the water and the denser object is completely inside the water. Now, the block is also allowed to completely enter the water and the combined system is again weighed. It weighs 80g. The relative density of the block is:
A 1/5
B 1/6
C 6/5
D 5/6

Answer 1

Answer:

A

Explanation:

please mark it as the brainliest answer

Answer 2

Answer:

Upthrust acting on the block in water =15N−12N=3N = ( volume of solid immersed )( density of liquid ) g = V (1) 10 where V is the volume of the block , so V=

10

3

=0.3 cm

3

Block weighs 15N in air implies 15=mg , implies m=

10

15

=1.5g

now density =

volume

mass

=

0.3

1.5

= 5 g/cm

3

so density of block = 5 g/cm

3

hence , relative density of the block = density of block / density of water=

1

5

=5

now Upthrust acting on the block in the liquid =15N−13N=2N= (volume of solid immersed ) ( density of liquid ) g=Vρg=0.3( ρ)g ,

implies ρ of the liquid =

3

2

g/cm

3

so relative density of the liquid = density of liquid / density of water =

1

3

2

=

3

2

so option (A) is correct

Explanation:

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