Question

A 20 m deep well with diameter 7m is dug and the earth from digging is evenly spread out to form a platform 22 m by 14 m find the height of the platform

Answer 1

Answer:

Step-by-step explanation:

Depth of well = 20m

Diameter= 7m

Radius =7/2= 3.5 m

DiMensions of cuboid÷

Length= 22m

Breadth=14m

Height=?

Now,

Volume of cylindrical well= volume of cuboidal embankment

On solving

We obtain,

H= 770/ 22×14

H= 5/2= 2.5m

Answer 2

⇒ Given:- Height (h) of well :- 20m

Diameter (d) :- 7 m

Radius (r) :- 7/2 m

Volume of earth platform :- 22 m by 14m

⇒ To find :- Height of the platform:- ?

⇒ Solution:-

Volume of cylinder of radius 7/2 m and height 20 m

Volume of cylinder :- π(r^2)(h)

= 22/7×(7/2^2)×20 m^3

= 770 m^3

Let the height raised by 22 m × 14 m platform be equal to h metres

Therefore,

Volume of the earth in platform = Volume of the earth taken out of the well

22 × 14 × h = 770

h = 770/22 × 14 m

h = 5/2 m

h = 2.5 m

Hence , the height of the platform is 2.5 m.