Question

How many cubic metres of earth must be dug out to sink a well which is 16 m deep and has a diameter of 14 cm if the earth taken out is spread over a rectangular plot 28 m by 24 m. What is the height of the platform so formed?​

Answer 1

Answer:

It is given in the question that,

Diameter = 7m

Hence, Radius = 3.5 m

Depth = 20 m

Volume of the earth to be dug out = π r 2 h πr2h = 22 7 × 3.5 × 3.5 × 20 227×3.5×3.5×20 = 770 m3

Volume of the earth piled upon the given plot = 28× 11 × h

Therefore, Height = 770 28 × 11 77028×11 = 70 28 7028 = 2.5m