4 A well of diameter 3 m is dug 14 m deep. The
Earth taken out of it has been spread evenly all
around it in the shape of a circular ring of width
4 m to form an embankment. Find the height of
the embankment.
Answers
As we got UNDERSTOOD that a well with Radius of 3/2m dugged at the HEIGHT of 14m.
The Earth is taken out simply means the VOLUME OF A WELL as a CYLINDRICAL SHAPE.
- πr²h = 22/7 × 3/2 × 3/2 × 14 = 99 M³
Now, As I'm getting that Earth spread around the dugged well in CIRCULAR RING OF WIDTH 4M which is same all around.
- so, New Diameter of the circular ring will be 3+(4+4) = 11m.
Henceforth, We must find the area into circular Ring excluding the area of CYLINDRICAL WELL.
→ πR²–πr² = π(R² – r²)
→ π([11/2]² – [3/2]²)
→ π([121/4] – [9/4])
→ π(112/4)
→ 22/7 × 28
→ 88 M²
Finally, It's time to find out Height or the raised embankment made from dugged EARTH.
Let the HEIGHT be x.
→ 99 = 88 × x → 9 = 8x
→ x = 9/8 ≈ 1.1 M