Question

The reading of a spring balance when a block is suspended from it in air is 60 newton. This reading is changed to 40 newton when the block is fully SUbmerged in water. The specific gravity of the block must therefore:

• A. 3
• B. 2
• C. 6
• D. 3/2

Answer 1

The correct option is A 3

Let m be mass ,
m$=$Dv ; D $=$ density of mass , v $=$ vol.
d $=$ density of water.
$m\times g=Dv\times g=60$
fully submerged in water
$(D-d)v\times g=40$
dividing both equations
$\frac{D-d}{D}=\frac{2}{3}$
solving this :
$\frac{D}{d}=3$