Question

The rain water from a roof of 44 m × 20 m drains into a cylindrical tank having diameter of base 4 m and height 3.5 m. If the tank is just full, then find the rainfall in cm.

Answer 1

We have,

The length of the roof, b = 20m,

The height of the cylindrical tank, H = 3.5 m and 

The base radius of the cylindrical tank, `R =4/2 =2  "m"`

Let the height of the rainfall be h.

Now,

volume of rainfall = Volume of cylindrical tank

⇒ lbh = πR²H

`rArr 44xx20xxh = 22/7xx2xx2xx3.5`

`rArr h = 22/7xx(2xx2xx3.5)/(44xx20)`

`"h" = 1/20 "m"`

`"h" =  100/20  "cm"`

∴ h = 5cm

So the height of the rainfall is 5 cm