Question

A cubical block of wood of side $5cm$ is placed on a table. Find the thrust by the block of wood on the table, if density of wood is $5g$ ${cm}^{-3}$ and $g$ is $10m$ $s^{-2}$.

Answer 1

Given,

Density of wood, $\rho =5gc{m}^{-3}$

$g=10m{s}^{-2}$

So, volume of cubical wood is $V=5^{3}c{m}^3=125c{m}^3$

$Density\left(\rho \right)=\frac{mass\left(m\right)}{Volume\left(V\right)}$

So

Mass of the wood is $m=\rho \times V=5\times 125=625g=625\times {10}^{-3}kg$

Thrust force, $T=Weight=m\times g=625\times {10}^{-3}\times 10=6.25N.$