Question

the volume of a metallic cylinder pipe is 748 cm cube is length is 14 cm and its external radius is 9 cm find its thickness.

Answer 1

Volume = 748 cm cube Length = 14 cm External Radius = 9 cm Thickness = ? radius = ?  Volume of pipe =  pie × h (R^2 - r^2) 748 = 22/7 × 14 (9^2 - r^2) 748 = 44 (9^2 - r^2) 748/44 = 81 - r^2 17 - 81 = - r^2 -64 = - r^2 ( minus minus cancel) r^2= 64 r = 8 Thickness = R - r                   = 9-8                   = 1 cm

Answer 2

Let x be the internal radius

Find the internal volume:

Volume = πr²h

Volume = 14πx²

Find the external volume:

Volume = πr²h

Volume = π(9)²(14) = 3564

Form equation and Solve x:

The difference in the 2 volume is 748 cm²

3564 - 14πx² = 748

14πx² = 3564 - 748

14πx² = 2816

x² = 2816 ÷ 14π

x² = 64

x = √64

x = 8

Find the thickness:

Thickness = 9 - 8 = 1 cm

Answer: The thickness is 1 cm