Question

The earth dug out of a well is spread evenly all around it to form an embankment which is 2 metre wide find the height of the embankment if the diameter of the well is 2 m and its depth is 20 m

Answer 1

Radius of the well (r) = 3/2 m = 1.5 m

Height of the well(h) = 14 m

Volume of the earth taken out of the well = πr2h = 22 7 ×(1.5)2×14 = 99 m3 .

Outer radius of the embankment R = 3/2 + 7 = 17 / 2 m

Area of embankment = outer area - inner area

⇒  πR2 - πr2 = (22/7)(17/2)2 - (22/7)(3/2)2

⇒ 22x17x17/28 - 22x9x9 / 28= 6358 / 28 - 198 / 28

= 6160 / 28 = 220 m2

∴ Height of the embankment = Volume / area = 99 / 220 = 9/20 = 0.45 m.

hope it helps mark brainliest plz