A wooden block is tied to a metallic rod of mass 100 g and immersed completely in water. When the displaced water is collected in a measuring jar, the volume of the liquid displaced is found to be 400 ml. If the density of the metallic rod is `"5 g cm", ^(-3)` and the mass of the wooden block is 300 g, determine the density of the wooden block.

Explanation

Mass of the metallic rod=100 g
Volume of the metallic rod+volume of wooden block=400ml
Density of the metallic rod `"5 g cm"^(-3)`
Volume of the metallic rod `=("mass of the metallic rod")/("density oof the rod")`
`=(100 g)/(5 g cm^(-3))=20 cm^(3))`
Volume of wooden the block = 400 - 20= `380 cm^3`
Mass of the wooden block =300 g
Density of the wooden block `=("mass")/("volume")=(300)/(380) = "0.79 g cm"^(-3)`