Question

A metallic hollow cylindrical pipe has outer and inner radii as 6 cm and 4 cm respectively. Find the volume of the metal used in the pipe of length of 14 cm.

Answer 1

Given, the pipe is in the shape of a hollow cylinder. Volume of a hollow cylinder of outer radius (R) and inner radius (r) with height (h).

= π(R² – r²) × h

Given, outer radius, R = 6 cm

inner radius, r = 4 cm

And height, h = 14 cm

∴ Volume of hollow pipe = π(6² – 4²) × 14

= ${\displaystyle \frac{22}{7}\times (36-16)\times 14}$

= 22 × 20 × 2

= 880 cm³

Hence, volume of metal used in the pipe is 880 cm³.