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A well with 14 m diameter is dug 8 m deep. The earth taken out of it has been evenly spread all around it to a width of 21 m to form an embankment. Find the height of the embankment. |
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Answer» We have, Diameter of well = 14 m Radius of well = d/2 = 14/2 = 7m Depth of well = 8 m Volume of earth dug out from well = πr2h = 22/7 × 7 × 7 × 8 = 1232 m3 This earth is spread out on width of 21 m. Area × h = 1232 π(R2 – r2) h = 1232 π(282 – 72) h = 1232 22/7 (735) h = 1232 h = 1232×7 / 22×735 = 8624/16170 = 0.533 m = 53.3 cm ∴ Height of embankment is 53.3 cm |
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