The outer diameter of a metallic pipe is 18 cm and the thickness of the pipe is 2 cm and the height is 4 cm . Find the surface area of the metallic pipe.
Answers
Find the outer radius:
Radius = Diameter ÷ 2
Outer Radius = 18 ÷ 2 = 9 cm
Find the outer surface area:
Outer surface area = 2πrh
Outer surface area = 2π(9)(4) = 72π cm²
Find the inner radius:
Thickness = 2 cm
Inner radius = 9 - 2 = 7 cm
Find the inner surface area:
Inner surface area = 2πrh
Inner surface area = 2π(7)(4) = 56π cm²
Find the area of both ends:
Area of 2 ends of the pipe = 2[ π(9)² - π(7)²] 64π cm²
Find the total surface area:
Total surface area = 72π + 56π + 64π
Total surface area = 192π
Total surface area = 603.43 cm²
Answer: 603.43 cm²
Given outer diameter of metallic pipe =18cm
(R) outer radius =9cm
Thickness =2cm
Then inner radius = 9−2=7cm
Height of pipe = 4cm
Pipe has a shape of cylinder then
Surface area of outer pipe = 2πRh = 2π×9×4
Outer area = 72πcm2
Inner surface area of pipe =2πrh=2×π×7×456π2cm
Now surface area of metallic pipe =72π−56π
Area =
Surface area of metallic pipe is =16πcm2