Question

A $20m$ deep well with diameter $7m$ is dug up and the length from digging is spread ----- to from a platform of dimmens $22m\times 14m$ . Determine the height of the platform .

Answer 1

Diameter of a well, $d=7m$
Radius of it , $r=\frac{7}{2}m$
$Depth/Height,h=20m$
Volume of eath takes out $=\pi r^{2}h$
$\frac{22}{7}\times \frac{7}{2}\times \frac{7}{2}\times 20=770m^3$
Let the height of plat form be ${}^{\prime }{H}^{\prime }$
$22\times 14\times H=770$
$\therefore H=\frac{770}{22\times 14}=\frac{5}{2}=2\frac{1}{2}m$
$\therefore$ The height of the plat form $=2\frac{1}{2}m$