The water supply to an old suburb in Perth is no longer adequate, and the water company is planning to put in a higher capacity supply. Which of the following options would give the biggest increase in the water flow into the suburb?
A) Re-route the water supply pipeline to a new route that is 13% shorter.
B) Dig up the water supply pipeline and replace it with one that has a 10% larger diameter.
C) Replace the pumps with ones that provide a 15% larger pressure difference.
D) Replace the buried water supply pipeline with one that is on the surface and hence exposed to the sun. The heat from the sun will warm the water and hence reduce its viscosity by around 7%.
E) All the other solutions will have the same results.ANS

Question

Quizplus · Accepted Answer

Increasing the diameter of the pipeline by 10% will increase the cross-sectional area by approximately 21% (since area is proportional to the square of the diameter). This will allow a larger volume of water to flow through the pipeline and into the suburb, resulting in the biggest increase in water flow. Re-routing the pipeline (option A) may reduce friction losses, but a 13% reduction in length is unlikely to have a significant impact. Likewise, increasing the pressure difference by 15% (option C) may increase flow, but not as much as increasing the diameter. Exposing the pipeline to the sun (option D) may slightly decrease viscosity, but this effect is not significant enough to make a significant difference in flow rate.

The Water Supply to an Old Suburb in Perth Is