A well with 14m diameter of is dug 8m deep. The earth taken out of it has been evenly spread all around it in the shape of a circular ring of width 21m to form an embankment. Find the height of the embankment.
Answers
Answered by
46
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 dis helps u
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 dis helps u
Answered by
20
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 dis helps u
Similar questions
Area of embankment = Pi (R^2 - r^2)
= 22/7 * (28^2 - 7^2)
= 22/7 * 35 * 21
= 2310 m^2
Therefore
Height of embankment 1232/2310 * 100 cm = 53.3 cm