Which term describes pressure when water is moving through the system?

• A. Dynamic pressure
• B. Static pressure
• C. Hydrostatic pressure
• D. Atmospheric pressure

Answer: (A)

When water is moving, part of what we measure as pressure comes from the fluid’s motion itself. This moving- water pressure is known as dynamic pressure and is tied to the velocity of the water (the faster it flows, the higher the dynamic pressure, mathematically described as 1/2 ρv^2). The term describes pressure that arises from the kinetic energy of the moving water.

Static pressure, on the other hand, is the pressure you’d measure if the fluid were not moving relative to the point where you’re measuring it; it’s the pressure due to molecular collisions in the fluid at that point, independent of flow speed.

Hydrostatic pressure is the pressure due to the weight of the water column when the fluid is at rest (depends on depth), so it’s about height in a standing fluid, not motion.

Atmospheric pressure is the pressure exerted by the surrounding air, not related to the water’s motion.

So, the pressure associated with water in motion is dynamic pressure.