Question

A well with 10 m inside diameter is dug 8.4 m deep. Earth taken out of it is spread all around it
to a width of 7.5 m to form an embankment. Find the height of the embankment. find the hight of embankment
​

Answer 1

Answer:

1.6m

Step-by-step explanation:

Radius (r) =10/2=5m

Depth (h) =8.4m

∴ Volume of earth dug out = πr*2h

=22/7×5×5×8.4m*3=660m*3

Width of embankment=7.5m

∴

Outer radius(R)=5+7.5=12.5m

Area of embankment = π(R*2−r*2= 22/7[(12.5)*2−5*2]. (a*2-b*2)=(a+b)(a-b)

= 22/7(12.5+5)(12.5−5)

=22/7×17.5×7.5 m*2

=412.5m*2

Let h be the height of embankment, then

Volume of embankment =412.5h=660

⇒h=660/412.5m

h=1.60m

Hope it help you❤❤