Question

the volume of clyindrical pipe is 748cm^3.Its lenght is 14 cm and external radius is 9cm .Find its thickness

Answer 1

open this picture dear

Answer 2

Answer:

1 cm

Step-by-step explanation:

Let the inner radius be r

Let the outer radius be R

We are given that external radius = 9 cm

So, R = 9 cm

Length of pipe h = 14 cm

Volume of cylindrical pipe = Outer volume - Inner volume

                                          =$\pi (R^2-r^2)h$

                                          =$\frac{22}{7}(9^2-r^2)14$

Since the volume of cylindrical pipe is 748 cubic cm.

So, $748 =\frac{22}{7} (9^2-r^2)14$

$\frac{748}{\frac{22}{7} \times 14}= 81-r^2$

$17=81-r^2$

$r^2=81-17$

$r^2=64$

$r=\sqrt{64}$

$r=8$

Thus the inner radius = 8 cm

So, width = Outer radius - Inner radius = 9 cm - 8 cm = 1 cm

Hence the width of the pipe is 1 cm.