h (t) F-

A necked-down section in a pipe flow, called a venturi, develops a low throat pressure that can aspirate fluid upward from a reservoir, as in Fig. P3.124. Using Bernoulli's equation with no losses, derive an expression for the velocity V, that is just sufficient to bring reservoir fluid into the throat. D, V2» P2=Pa Water V Pa Water Р3.124

In Fig. P3.131 both fl uids are at 20 ° C. If V 1 = 1.7 ft/s andlosses are neglected, what should the manometer readingh ft be?

The rocket in Fig. P3.68 has a supersonic exhaust, and theexit pressure p e is not necessarily equal to p a . Show that theforce F required to hold this rocket on the test stand isF = ρe AeV2e+ Ae( pe - pa) . Is this force F what we termthe thrust of the rocket?

Consider Fig. P3.36 as a general problem for analysis of amixing ejector pump. If all conditions ( p , ρ , V ) are knownat sections 1 and 2 and if the wall friction is negligible,derive formulas for estimating ( a ) V 3 and ( b ) p 3 .

The 35 °C water fl ow of Fig. P3.135 discharges to sea-levelstandard atmosphere. Neglecting losses, for what nozzlediameter D will cavitation begin to occur? To avoidcavitation, should you increase or decrease D from thiscritical value?

P3.21 For the two-port tank in Fig. E3.5, let the dimensions remain the same, but assume V₂ = 3 ft/s and that V₁ is unknown. If the water surface is rising at a rate of 1 in/s, (a) determine the average velocity at section 1. (b) Is the flow at section 1 in or out?

answer very quickl

Water from a storm drain fl ows over an outfall onto aporous bed that absorbs the water at a uniform verticalvelocity of 8 mm/s, as shown in Fig. P3.19. The system is5 m deep into the paper. Find the length L of the bed thatwill completely absorb the storm water.