Problem 61PE

Unreasonable Results

A fairly large garden hose has an internal radius of 0.600 cm and a length of 23.0 m. The nozzleless horizontal hose is attached to a faucet, and it delivers 50.0 L/s. (a) What water pressure is supplied by the faucet? (b) What is unreasonable about this pressure? (c) What is unreasonable about the premise? (d) What is the Reynolds number for the given flow? (Take the viscosity of water as 1.005×10–3 N(/m2) ⋅ s .)

Solution 61PE

a.)

P2 = + 1.01x105 N/m2

=22.7 x 105 N/m2 + 1.01 x 105 N/m2

= (23.7 x 105 N/m2)

= 344 Ib/in2

The water pressure supplied by the faucet is 344 Ib/in2.

b.)

The unreasonable fact about the pressure is that it is very high.

c.)

The unreasonable fact about the premise is that the flow rate is very high for a garden hose.

d.)

NR =

= 5.27 x 106

The Reynold’s number is = 5.27 x 106

.