Question

A cylindrical metal pipe of thickness 1.4 cm and external diameter 56 cm is 14 m long.Find the volume of metal ised in the construction of the pipe.

Answer 1

Answer:

Volume of metal used is 0.3362 m³

Step-by-step explanation:

Length of the pipe L = 14 m

External dia of the pipe = 56 cm

External radius of the pipe r₁ = 56/2 = 28 cm

Internal dia of the pipe = 56 - 1.4 - 1.4 = 53.2 cm

Internal radius of the pipe r₂ = 26.6 cm

Volume of the metal used

= Volume of the external cylinder - Volume of the internal cylinder

$=\pi r_1^2L-\pi r_2^2L$

$=\pi L(r_1^2-r_2^2)$

$=\pi \times 14[(28\times 10^{-2})^2-(26.6\times 10^{-2})^2)$

$=\pi \times 14\times 10^{-4}[(28\times 10^{-2})^2-(26.6\times 10^{-2})^2)$

$=\pi \times 14\times 10^{-4}(784-707.56)$

$=3.14 \times 14\times 76.44\times 10^{-4}$

$=0.3362$ m³

Answer 2

Step-by-step explanation:

volume of metal used is 336336 cm2