Question

A cylinder of certain mass is held in vertical position. If the height of the cylinder is $10cm$ and radius of cross-section is $4cm$ such that the pressure acting on its bottom surface is $21560N{m}^{-2}$, then find the mass of the cylinder?

Answer 1

We know pressure is $P=\frac{weight}{area}$

$A=\pi r^2=\pi \times (4\times {10}^{-2}{)}^2{m}^2=16\pi \times {10}^{-4}$ $m^2$

$P=21560N/m^2$

So

$P=21560=\frac{mg}{16\times \pi \times {10}^{-4}}$ , $g=10m/s^2$

So $m=10.8Kg$