Question

A heap of wheat is in the form of a cone of diameter 9m and height 3.5m. Find its volume. How much canvas cloth is required to just cover the heap? `(U s e pi=3. 14)`

Answer 1

Correct Answer - `74.1825 m^(3), 80.54 m^(2)`
`r = (9)/(2) m and h = (7)/(2)m`
`:.` volume `= (1)/(3) pi r^(2) h = ((1)/(3) xx 3.14 xx (81)/(4) xx (7)/(2)) m^(3) = 74.1825 m^(3)`
`l^(2) = (r^(2) + h^(2)) = ((81)/(4) + (49)/(4)) = (130)/(4) rArr l = (sqrt(130))/(2) = (11.4)/(2) = 5.7 m`
Area of canvas `= pi rl = (3.14 xx (9)/(2) xx (57)/(10)) m^(2) = 80.54 m^(2)`