I think that my textbook has too little example questions on this topic illustrating the concepts, so I have some confusions when I attempt to solve the following problems for practice. I hope someone would be nice to clarify such concepts. Any help is greatly appreciated!(adsbygoogle = window.adsbygoogle || []).push({});

1) River A with a volume flow rate of 8x10^4 L/s joins with River B, which carries 11x10^4 L/s, to form River C. River C is 120m wide and 10m deep. What is the speed of the water in River C?

I know from the equation of continuity that Q=vA=constant where Q is volume flow rate, v is speed, A is area. Now I need Q and A in order to find v, is Q simply 19x10^4 L/s and is A simply the area of a rectange 120mx10m=1200m^2 ? Are the calculations really that simple or am I wrong?

2) Water is flowing out of a 10mm diameter sink faucet at 0.4m/s, at what distance below the faucet has the water stream narrowed to 5mm diameter?

v1A1=v2A2

0.4*pi*(0.01)^2 = v2*pi*(0.005)^2

v2=1.6m/s

This is what I am thinking, but in this case the water is falling and is affected by gravity, will the equation of continuity Q=vA=constant still hold? And is the water as simple as free falling at a constant acceleration of 9.8m/s^2?

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# Homework Help: Fluid Mechanics (2)

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