Question

A heap of wheat is in the form of a cone of diameter 16.8 m and height 3.5 m. Find its volume. How much cloth is required to just cover the heap?

Answer 1

Diameter of the cone = 16.8 m

Therefore, radius (r) = 8.4 m

Height (h) = 3.5 m 

i. Volume of heap of wheat = `1/3pir^2h`

= `1/3 xx 22/7 xx (8.4)^2 xx 3.5`

= `1/3 xx 22/7 xx 8.4 xx 8.4 xx 3.5` 

= 258.72 m³ 

ii. Slant height (l) = `sqrt(r^2 + h^2)` 

`sqrt((8.4)^2 + (3.5)^2)` 

= `sqrt(70.56 + 12.25)` 

= `sqrt(82.81)` 

= 9.1 m 

Therefore, cloth required or curved surface area = πrℓ 

= `22/7 xx 8.4 xx 9.1` 

= 240.24 m²