Question

A metallic block of density $5gm{cm}^{-3}$ and having dimensions $5cm\times 5cm\times 5cm$ is weighed in water. Its apparent weight will be

• A. $5\times 5\times 5\times 5\times gf$
• B. $4\times 4\times 4\times 4\times gf$
• C. $5\times 4\times 4\times 4\times gf$
• D. $4\times 5\times 5\times 5\times gf$

Answer 1

The correct option is D $4\times 5\times 5\times 5\times gf$

It is known that:

apparent weight = weight in air $[1-\frac{1}{\sigma }]$

$=V\rho g[1-\frac{1}{\sigma }]$

$=125\times 5\times 9.8[1-\frac{1}{5}]$

$=4.9N$

or

$4\times 5\times 5\times 5$ for relative density

Hence option D is correct