Question

A well with 10 m inside diameter is dug 14m deep. Earth taken out of it is spread all around it to make an embankment of height 14/3 m. Find the width of the embankment.​

Answer 1

Answer:

Given,

Internal diameter(d)=10m

Height(h)=14m

Volume of soil taken out

=((πxd²)÷4)x14 m³

=((3.14x10²)÷4)x14 m³

=78.5x14 m³

=1099.0 m³

Given, embankment width 5m

I.e, internal diameter of embankment=10m

So, internal radious (r)=10÷2=5m

External diameter of embankment

=(10+5)=15m

So,external radious (R)=15÷2 =7.5m

Area of embankment

=2π(R²-r²) m²

=2x3.14x(7.5²-5²) m²

=196.25 m²

Now,

Height of embankment

=1099.0÷196.25 m

=5.6 m

Height of embankment is 5.6m