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A shower spray unit with a hose of ___ long minimum that can be used as a fixed-position shower head and as a hand-held shower shall be provided.

User Aaron Liu
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Final answer:

Using principles from fluid dynamics, the question involves determining the water pressure from a faucet, the reasonableness of this pressure, and the premise of the flow rate from a garden hose. Calculations yield an unreasonably high pressure and flow velocity, and the computed Reynolds number corroborates that the premise is unlikely. The response unpacks the reasons for these unreasonable results by referencing fluid flow equations.

Step-by-step explanation:

To determine the water pressure supplied by the faucet, we use the equation of continuity and Bernoulli's equation for fluid flow. The hose delivers a high flow rate, which leads to a calculation involving a high water pressure. Given the internal radius (r) of 0.600 cm or 0.006 m and the volume flow rate (Q) of 50.0 L/s or 0.050 m3/s, velocity (v) can be found using Q = vπr2. However, the velocity calculated from the given flow rate and hose dimensions is found to be much higher than the typical velocity of 1.96 m/s for water emerging from a nozzleless hose, indicating an unreasonable pressure. Moreover, the premise of a hose delivering such a high flow rate without a nozzle calls into question the practicality of such a setup.

The Reynolds number is a dimensionless quantity that helps predict flow patterns in different fluid flow situations. It is calculated using the formula Re = (vdρ)/η, where v is the velocity of the liquid, d is the diameter of the hose, ρ (rho) is the density of the liquid, and η (eta) is the dynamic viscosity of the liquid. For water at room temperature ρ is approximately 1000 kg/m3 and η is given as 1.005 × 10−3 (N/m2) · s.

Using these values, the Reynolds number can be estimated, which reflects whether the flow is laminar or turbulent. The calculated Reynolds number for the given situation would be unrealistically high, suggesting turbulent flow, further questioning the premise.

User Lefteris S
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