What is the unit used for the friction loss factor for rise in elevation?

What is the unit used for the friction loss factor for rise in elevation?

• A. kPa per meter
• B. kPa
• C. psi per foot
• D. bar per meter

Answer: (A)

When you account for rise in elevation, you’re dealing with how much pressure is required to support water at a higher point per unit of vertical distance. That means the friction loss (or head loss) factor is a pressure change per length of rise, i.e., pressure gradient with respect to height. In metric terms, this is kilopascals per meter, because 1 meter of water elevation requires about 9.81 kPa of pressure. Therefore, the unit used for the friction loss factor for rise in elevation is kPa per meter. The other options don’t fit this idea: a plain kPa is just a fixed pressure value, not a rate per distance; psi per foot is an imperial unit for a gradient but the listed correct answer reflects the metric unit; bar per meter is conceptually similar but less standard for this specific context.

When you account for rise in elevation, you’re dealing with how much pressure is required to support water at a higher point per unit of vertical distance. That means the friction loss (or head loss) factor is a pressure change per length of rise, i.e., pressure gradient with respect to height. In metric terms, this is kilopascals per meter, because 1 meter of water elevation requires about 9.81 kPa of pressure. Therefore, the unit used for the friction loss factor for rise in elevation is kPa per meter.

The other options don’t fit this idea: a plain kPa is just a fixed pressure value, not a rate per distance; psi per foot is an imperial unit for a gradient but the listed correct answer reflects the metric unit; bar per meter is conceptually similar but less standard for this specific context.