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प्रश्न
A 14 m deep well with inner diameter 10 m is dug and the earth taken out is evenly spread all around the well to form an embankment of width 5 m. Find the height of the embankment.
उत्तर
Radius of the well (r1) = 5 m
Depth of the well (h) = 14 m
Width of the embankment = 5 m
Outer radius (R) = 5 + 5 = 10 m
Let the height of the embankment be H
Volume of Earth in the embankment = Volume of the well
πH(R2 – r2) = `pi"r"_1^2"h"`
H(102 – 52) = 5 × 5 × 14
H(100 – 25) = 5 × 5 × 14
H = `(5 xx 5 xx 14)/75`
= 4.67 m
Height of the embankment = 4.67 m
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