Question

a well with diameter 7m inside diameter is dug 22.5m deep.Earth taken out it has been spread all round it to a width of 10.5m to form an embankment.Find the height of the embankment so formed.

Answer 1

See the attached file for solution. Thanks

Answer 2

Answer:

1.5 m

Step-by-step explanation:

Diameter of well= 7 m

Radius of well r = Diameter /2 = 7/2 = 3.5 m

Depth of well = 22.5 m

Since well is in the shape of cylinder

Volume of well = $\pi r^2 h$

= $3.14 \times (3.5)^2 \times 22.5$  

= $865.4625$  

Now we are given that .Earth taken out it has been spread all round it to a width of 10.5 m to form an embankment.

So, Volume of embankment is equal to volume of well

So, outer radius R = 3.5+10.5 = 14 m

Let the height of embankment be h

Volume of embankment = $\pi (R^2-r^2)h$

$865.4625=3.14 (14^2-3.5^2)h$

$865.4625=576.975h$

$\frac{865.4625}{576.975}=h$

$1.5=h$

Hence the height of embankment is 1.5 m