Question

The mass of an wooden cube of edge 10 cm is 800 g. If the mass of an equal volume of water is 1 kg, then the relative density of a wooden cube is $8\times {10}^{-x}$. Find the value of x.

Answer 1

Relative density $=$ (density of a substance / density of water)

Here, density of wooden cube $=M_c/V=800/{10}^3=8\times {10}^{-1}g/c{m}^3$

Density of water $=m_w/V=1000/{10}^3=1g/c{m}^3$

Thus, relative density $=\frac{8\times {10}^{-1}}{1}=8\times {10}^{-1}$

Hence, comparing the given value, $x=1$