Question

Calculate the inner area (cross sectional) of a pipe with an outer diameter of 300mm and a

thickness of 5mm.
What length of pipe can be manufactured from 10^6 cm^3 material?​

Answer 1

46.3 cm²

216 m

Step-by-step explanation:

The cross sectional area is the area of the outer circle minus the area of the inner circle.

A = πR² − πr²

R = 300/2 = 150 mm = 15 cm

r = 150 − 5 = 145 mm = 14.5 cm

A = π (15 cm)² − π (14.5 cm)²

A ≈ 46.3 cm²

Volume is area times length:

V = AL

10⁶ cm³ = (46.3 cm²) L

L ≈ 21,580 cm

L ≈ 216 m