Question

6. A circular pit measuring
14 m in diameter and
with depth 4 m is
required to be levelled
with earth. The earth
is to be dug out from a
rectangular field measuring 22 m x 8m. Up to what
depth should the field be dug out to completely fill
the circular pit?​

Answer 1

Answer:

The height of the rectangular platform is 3.5 m

Step-by-step explanation:

 Earth is dug in the form of cylinder

volume of the earth dug = volume of the cylinder = πr²h

Radius r = 14/2 = 7 m

depth h = 4m

hence volume of earth dug

= 22/7 x 7 x 7 x 4

= 616 m³

This volume of earth dug should be equal to volume of cuboid = L x B x h

given L = 22 m

B = 8 m

hence

22 x 8 x h = 616

=> h = 616/176 = 3.5m

Hence the height of the rectangular platform is 3.5 m