Question

a conical pit of top diameter 3.5m is 12 m is deep .what is its capacity in kilolitres

Answer 1

d=3.5m
r=3.5/2
h=12m
Volume of pit=1/3πr^2h
=1/3×22/7×3.5/2×3.5/2×12
=38.5m^3
1m^3=1000l=1kl
1m^3=1kl
Capacity in kl=38.5kl

Answer 2

$\Large{\textbf{\underline{\underline{According\:to\:the\:Question}}}}$

Diameter = 3.5

$\tt{\rightarrow Radius=\dfrac{3.5}{2}}$

$\tt{\rightarrow Radius=\dfrac{7}{4}}$

Height (Depth) = 12m

Now,

${\boxed{\sf\:{Volume\;of\;Cone}}}$

$\tt{\rightarrow\dfrac{1}{3}\times\pi r^2h}$

$\tt{\rightarrow\dfrac{1}{3}\times\dfrac{22}{7}\times\dfrac{7}{4}\times\dfrac{7}{4}\times 12m^3}$

$\tt{\rightarrow\dfrac{11\times 7}{2}m^3}$

[1m³ = 100³ cm³]

$\tt{\rightarrow\dfrac{11\times 7}{2}\times(100\times 100\times 100)cm^3}$

$\tt{\rightarrow\dfrac{11\times 7}{2}\times 10^{6}cm^3}$

[1 litre = 1000 cm³]

$\tt{\rightarrow\dfrac{11\times 7}{2}\times 10^{6}\times\dfrac{1}{10^{3}}litre}$

[1000 litre = 1kilolitre]

$\tt{\rightarrow\dfrac{11\times 7}{2}\times 10^{6}\times\dfrac{1}{10^{3}}\times\dfrac{1}{10^{3}} Kilolitre}}$

$\tt{\rightarrow\dfrac{11\times 7}{2}kilolitre}$

$\tt{\rightarrow\dfrac{77}{2}kilolitre}$

= 38.5 kilolitres