Nozzle reaction is measured in pounds of force and is a function of which two factors?

Nozzle reaction, which refers to the force exerted back on the firefighter using a nozzle, is primarily a function of flow rate and nozzle pressure. This relationship stems from the principles of fluid dynamics, where the amount of water flowing through the nozzle (flow rate) and the pressure at which this water exits (nozzle pressure) directly influence the resulting reaction force experienced by the firefighter.

As the flow rate increases, more water is being pushed through the nozzle, which thereby increases the force generated in the opposite direction (nozzle reaction). Similarly, higher nozzle pressure means that the water is exiting with greater force, increasing the reaction experienced by the user as well. Understanding this relationship is crucial for firefighters, as it allows them to anticipate and manage the forces involved when operating hoses and nozzles effectively and safely.

Other factors, such as tank pressure, water temperature, nozzle design, and friction loss, do have their respective impacts on water delivery and operation, yet they do not directly relate to the calculation of nozzle reaction in the context described.