15. A new section of 12-inch diameter pipe is to be disinfected before it is put into service. If the length of the pipeline is 1200 feet, how many gallons of water will be needed to fill it?

7050 gallons

Step-by-step explanation:

The pipe is cylindrical, so the volume is:

V = πr²h

Given:

r = 12/2 = 6 inches = 0.5 feet

h = 1200 feet

Substituting:

V = π (0.5 ft) ² (1200 ft)

V = 942.5 ft³

One cubic foot is 7.48 gallons, so:

V = 7050 gallons