the outer diameter of metalic 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
━━─━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
☃ ƛƝƧƜЄƦ ☃
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
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Answer:
Given outer diameter of metallic pipe
=
18
cm
(R) outer radius
=
9
cm
Thickness
=
2
cm
Then inner radius
=
9−
2=
7 cm
Height of pipe
=
4
cm
The pipe has a shape of the cylinder then
The surface area of outer pipe
=
2πRh
= 2π× 9× 4
Outer area
=
72π cm
2
Inner surface area of pipe
=
2πrh=
2×
π×
7×
4
= 56π cm
2
Now surface area of metallic pipe
=
72π−
56π
Area
=
16π cm
2
∴ Surface area of metallic pipe is 16π cm
2
.