a 40m deep well with radius 3.5m is dug and the earth taken out is evenly spred to form aplat form of dimenshins 28m by 22m find the heght of theplat form?

3 answers

56
thickness = volume/area
so,
thickness = (π*3.5^2*40)/(28*22) = 2.5m
Vw = pi*r^2*d = 3.14 * 3.5^2 * 40 = 1539 m^3. = Vol. of well.

Vp = L*W*h = 1539.
28 * 22 * h = 1539,
h = 2.5 m.