3. Pipe wall thickness: What wall thickness (in centimeters) is necessary for a 6-inch diameter PVC pipe to withstand an internal pressure of 50 psia. The tensile strength (Otens) of

PVC is approximately 4,500 psi. Assume that the pipe is 6-inch in internal diameter. Perform this calculation twice, once with no safety factor, and a second time with a 70% safety factor.