The length of inner and outer diameter of a right circular cylindrical pipe open at two ends are 30 cm and 26 cm respectively and length of pipe is 14.7 m. Let us write by calculating the cost of painting its all surfaces with coaltar at Rs 2.25 per sq.dcm.

Given:

The length of inner and outer diameter of a right circular cylindrical pipe open at two ends are 30 cm and 26 cm respectively and length of pipe is 14.7 m.

To do:

We have to find the cost of painting its all surfaces with coaltar at Rs 2.25 per sq.dcm.

Solution:

Radius of the inner surface of the pipe $=\frac{Inner\ diameter}{2}=\frac{26}{2}=13\ cm$

Radius of the outer surface of the pipe $=\frac{Outer\ diameter}{2}=\frac{30}{2}=15\ cm$

Height(length) of the pipe $=14.7\ m=14.7\times100=1470\ cm$

Inner surface area of the pipe $=2\pi(13)(1470)\ cm^2$

$=2\frac{22}{7}\times\frac{13\times1470}{10\times10}$ sq.dcm

$=1386$ sq.dcm

Outer surface area of the pipe $=2\pi(15)(1470)\ cm^2$

$=2\frac{22}{7}\times\frac{15\times1470}{10\times10}$ sq.dcm

$=1201.2$ sq.dcm

Total surface area $=$ Outer surface area $+$ Inner surface area

$=1386+1201.2$ sq.dcm

$=2587.2$ sq.dcm

Rate of painting $=Rs 2.25$ per sq.dcm.

Total cost of painting $=2.25\times2587.2$

$=Rs.\ 5821.20$

Tutorialspoint

Updated on: 10-Oct-2022

79 Views

Kickstart Your Career

Get certified by completing the course

Get Started