Question

If a wood is drowned in water up to 2/3 of its volume and the same wood is dipped in a oil upto 9/10 of its volume.What's the density of wood and the relative oil?
Density of water -1000kgm-3

Answer 1

S.G. or specific gravity is the ratio of the density of an object to a fluid. It also is the fraction of the object's volume that would be submerged if the object were placed in the fluid. (note: if S.G.>1, the object will sink)

S.G. = density(wood) / density(water)

2/3 = density(wood) / 1000

density(wood) = 2000/3 kg/m^3 = ~666.67 kg/m^3

S.G. = density(wood) / density(oil)

9/10 = 2000/3 / density(oil)

density(oil) = 2000/3 / 9/10 = 20000/27 kg/m^3 = ~740.74 kg/m^3