In a fluid flow system, if two sections of a pipe have similar cross-sectional areas, what can be said about the flow speed in these sections according to the continuity equation?

A fire hose exerts a force on the person holding it due to the water accelerating as it goes from the thicker hose out through the narrow nozzle. How much force is required to hold a 7.0-cm-diameter hose delivering 480 L/min through a 0.75-cm-diameter nozzle?

(II) A 5/8 -in. (inside) diameter garden hose is used to fill a round swimming pool 6.1 m in diameter. How long will it take to fill the pool to a depth of 1.4 m if water flows from the hose at a speed of 0.40 m/s?

What must be the pressure difference between the two ends of a 1.6-km section of pipe, 29 cm in diameter, if it is to transport oil (ρ = 950 kg/m³, η=0.20 Pa⋅s) at a rate of 650 cm³/s?