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2014-10-02T14:03:42+05:30

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So we know well is cylinder
    

radius = 11.2 /2 = 5.6 m
height = 8 m 
so volume of earth dig
   
πr²h
= 22/7 × 5.4² × 8
= 787.76 m³

so spreading will create a hollow cylinder
 
let the height be  h
so 
formula for volume of hollow sphere is 
πh(r₂²-r₁²)
787.76 = πh(12.4²-5.6²)
h=787.76/π(12.4²-5.6²)
h = 1.97 m
0
Please check your solution. Edit it.
thnks fr ur try
2014-10-02T15:30:44+05:30

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Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
Diameter of well = 11.2m
radius(r) = 5.6m
depth (h) = 8m
The earth taken out = The volume of the well = V
V = πr²h = π×5.6²×8 m³

As the volume of earth taken has been used to make the embankment, the volume of embankment is the same as volume of well.
A circular embankment is a hollow cylinder with some width
In this case  width(w) = 7m.
The inner radius of embankment(r1) = 5.6m (same as the well)
       outer radius of embankment(r2) = (r1+w) = (5.6+7)m = 12.6m
Let the height = h1 m

Volume of embankment = volume of well
⇒π×h1×[(r2)² - (r1)²] = πr²h
⇒ π×h1×[(r2)² - (r1)²] = π×5.6²×8
⇒ h1×[12.6² - 5.6²] = 5.6²×8
⇒ h1 = (5.6²×8) / (12.6²-5.6²)
⇒ h1 = 1.97m

Height of embankment is 1.97m


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