Question

a cylindrical piece of iron pipe is shown below. the wall of the pipe is 1.25 inch thick. what is the approximate inside volume of the pipe? 154 cubic inches 142 cubic inches 49 cubic inches 88 cubic inches

Explanation:

Step1: Find inner - radius

The outer diameter of the pipe is 6 inches, and the wall thickness is 1.25 inches. So the inner - diameter $d=6 - 2\times1.25= 6 - 2.5 = 3.5$ inches. Then the inner - radius $r=\frac{3.5}{2}=1.75$ inches.

Step2: Apply cylinder volume formula

The volume formula for a cylinder is $V=\pi r^{2}h$, where $h = 16$ inches (height of the cylinder). Substitute $r = 1.75$ inches and $h = 16$ inches into the formula: $V=\pi\times(1.75)^{2}\times16$.

Step3: Calculate the volume

First, $(1.75)^{2}=3.0625$. Then $V=\pi\times3.0625\times16=50\pi$. Using $\pi\approx3.14$, we get $V\approx50\times3.14 = 157$ cubic inches. The closest value among the options is 154 cubic inches.

Answer:

154 cubic inches