Question

a well of diameter 10 m is dug 14 m deep. the earth taken out is spread evenly to form a rectangular platform of base 11 m x 10 m .find the height of the platform​

Answer 1

Well with diameter 10 m is dug 14 m deep.

= cylindrical radius =10/2 m = 5m

Volume = πr square h

=22/7 × 5 × 5 × 14

=1100 cubic metres

1100 cubic metres is taken out and spread width of 5 m.

R1 = 5+5 m =10 m

So, r = 5 m

V = π(R square - r square) h

1100 = 22/7 (10 square - 5 square) h

350 = (100 -25 ) h

h = 350/75

h = 14/3

h = 4.66 m.

Hence, the height of platform is 4.66 m