Example - continued
answer: Q = 4x10-5m3/s = 40 cc/sec
What pressure difference is needed to have this flow through a hose of length 20 m ?
Q = ???P)R4 / (8?L) = 4 x 10-5 m3 /sec
R = (1/2)*.0254 m; ? = 1 x 10-3 Pl; L = 20 m
8(1x10-3)(20)(4x10-5)/(?[.01274]) Nt/m2
= 78 Nt/m2 * (760 mmHg/1.01x105 Nt/m2) = 0.6 mmHg