Question

The mass of an empty bucket of capacity $10$ liters is 1 kg. Find its mass (in kg) when completely filled with a liquid of relatively density $\mathrm{0.8.}$

Answer 1

Given,

${\rho }_w=1000kg/m^3$

Mass of the empty bucket, $m=1kg$

The volume of the bucket, $V=10l=10\times {10}^{-3}=0.01m^3$

The relative velocity of the liquid to be completely filled with the water, $s=0.8$

The density of the liquid, ${\rho }_l=s\times {\rho }_w$

${\rho }_l=0.8\times 1000=800kg/m^3$

Now, the mass of the liquid when filled in the bucket,

$m_l={\rho }_{l}V=800\times 0.01$

$m_l=8kg$

The total mass of bucket when filled with the water,

$M=m+m_l=1+8=9kg$

$M=9kg$