How to Calculate Tube
What is Tube?
A tube (hollow cylinder) has an outer radius R and inner radius r. Volume = π(R² − r²) × length. Surface area includes outer surface, inner surface, and the two ring-shaped ends. Used for pipes, ducts, and hollow shafts.
Step-by-Step Guide
- 1Wall thickness = R − r (outer minus inner radius)
- 2Cross-sectional area = π(R² − r²)
- 3Volume = π(R² − r²) × length
- 4Total SA = 2π(R+r)×length + 2π(R²−r²) (lateral + ends)
Worked Examples
Input
Outer R=5, inner r=3, length=20
Result
V = π(25−9)×20 = 1,005.3 cubic units
Wall thickness = 2 units
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