Question

how many cubic metres of earth must be dug out to sink a well 16 m in depth and 7 m in diameter ​

Answer 1

Answer:

$height \: of \: well = 16m \\ radius \: of \: well = \frac{7}{2} \\ \\ \\ volume \: of \: well = \pi {r}^{2} h \\ \\ = \frac{22}{7} \times \frac{7}{2} \times \frac{7}{2} \times 16 \\ \\ = 616 {m}^{3} \\ \\ volume \: dugged \: is \: 616 {m}^{3} ...... \\ \\ so...volume \: dugged \: is \: 616000000 {cm}^{3} \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 616 \times {10}^{6} {cm}^{3} .....$

hope it helps........✌✌

Answer 2

Answer:

if we'll is in shape of cylinder then amount of earth to be dug=volume of cylinder=π×r×r×h=π×12.25×16=615metre cube