Question

a cylindrical tank has a capacity of 6160cu cm find its depth if its radius is 14 M calculate the cost of painting its curved outer surface at the rate of ₹3 per square metre

Answer 1

$\Longrightarrow{\boxed{\bold{Answer:h = 0.001 cm}}}$

$\Longrightarrow{\boxed{\bold{and\:Cost =0.264\:p}}}$

$\textbf{\underline{Step-by-step explanation :- }}$

Changing units we get,

14 m = 14 × 100 cm = 1400 cm

Now, volume of cylinder = πr²h

Volume of cylinder = 6160 cm³

πr²h = 6160 cm³

22/7 × (1400)² × h = 6160 cm³

6160000h = 6160 cm

h = 6160/6160000

$\bold{\huge{h = \frac{1}{1000}}}$

$\bold{\huge{\underline{=0.001\:cm}}}$

Now, curved surface area of cylinder = 2πrh

= 2 × 22/7 × 1400 cm × 0.001 cm

= 2 × 22 × 200 cm × 1/1000 cm

= 8800/1000 cm²

$\bold{\huge{\underline{= 8.8\:cm^2}}}$

Now, 1 cm² = 1/10000 m²

= 8.8/10000 m²

= 0.00088 m²

Now cost of painting = 0.00088 × Rs 3

$\bold{\underline{= Rs\:0.00264\:or\:0.264\:paise}}$