Final answer:
The number of water pumping stations is influenced by elevation change, which dictates the potential energy required to transport water. Higher elevations require pumps to provide greater pressure to ensure adequate water flow rates to the desired locations.
Step-by-step explanation:
The number of water pumping stations required for a water supply system is influenced by several factors, including the distance over which water must be transported and the terrain's elevation changes. The correct answer is b) elevation change. A change in elevation dictates the potential energy required to transport the water, which informs the number and power of the pumps needed. For instance, water must be pumped to higher kinetic energy levels to overcome elevation differences, and the greater the elevation, the more pressure the pump must provide.
In calculating the pressure provided by a pump to transport water up a hill, the energy required for this increase in potential energy as height increases is a crucial factor. This concept aligns with the principle of continuity equation and the work done by pressure to increase kinetic and potential energy. For example, if a pump is supplying water to a house located 150 m vertically upward, it must provide sufficient pressure to overcome this elevation gain plus any additional pressure needed to achieve the desired flow rate at the house.