Question

A length of metal pipe has a circumference of 2.5 inches. the pipe is 1/16 inches thick. a gas fitter needs to know the inside diameter of the pipe to calculate the gas pressure. What is the total diameter of pipe including metal? how much of the diameter is metal? what is the inside diameter of the pipe?

Answer 1

The circumference is
C = πd
The diameter of the metal pipe is
d = C/π = 2.5/π = 0.796 inches

The total diameter is still 0.796 inches because the diameter of the metal pipe is greater than the inside pipe. Imagine that the pipe is inserted, so there are no changes in size. Of course, the pipe is also a hollow cylinder.

The diameter of the inside pipe is actually given, 1/16 inches.