A block of wood weights 16 kg in air. A lead block which has apparent weight of 28 kg in water is attached to the block of wood, and both of them are submerged in water If their combined apparent weight in water is 19 kg find the density of wooden block in `kg//m^(3)` Take density of water `=1000 kg//m^(3)` .

Answer

`0640`

Explanation

`rho_(w) v_(w)=16 rho_(x)=density of H_(2)O`
`rho_(L)V_(L) - rho_(H) V_(L) = 28`
`rho_(L) V_(L) + rho_(w) w_(w)-rho_(H)(V_(L)+V_(w))=19`
Rightarrow `16-rho_(H) V_(w)+28=19`
`rho_(H) V_(w)=25`
Rightarrow`(rho_(w))/rho_(H) = 16/25 Rightarrow rho_(w)=16/25xx1000=640 kg//m^(3)`