Question

the volume of a cylindrical pipe is 748 cm3 its length is 14 cm and its external radius is 9 cm find its thickness

Answer 1

that's the answer for the above mentioned question

Answer 2

Answer:

The volume of a cylindrical pipe is 748 $cm^{3}$ Then its thickness is 8 cm

Solution:

Given that:

Height of the cylindrical pipe (h) = 14cm

Let the external radius of the cylindrical pipe be “R” = 9 cm

Let the internal radius be “r”

Volume of cylindrical pipe = 748 $cm^{3}$

Volume of cylinder when external and internal radius are given is:

$\text { Volume }=\pi h\left(R^{2}-r^{2}\right)$

Substituting the values we can find the thickness of pipe “r”:

$\begin{array}{l}{748=\pi \times 14\left(9^{2}-r^{2}\right)} \\\\ {748=\frac{22}{7} \times 14\left(81-r^{2}\right)} \\\\ {748=44\left(81-r^{2}\right)} \\\\ {\frac{748}{44}=81-r^{2}} \\\\ {17=81-r^{2}} \\\\ {r^{2}=81-17=64}\end{array}$

r = 8 cm

Thus the thickness of pipe is 8 cm