圖片參考：http://imgcld.yimg.com/8/n/HA00414085/o/701202290038813873443230.jpg
A pipe X of cross-sectional area 24 cm^2 branches into two smaller pipes, Y of area 15 cm^2 and Z of area 6 cm^2. An incompressible liquid flows through the pipes and travels at a speed of 0.4 ms^-1 in X and 0.6 ms^-1 in Y. What is the speed of the fluid in Z?
A. 0.1 ms^-1
B. 0.2 ms^-1
C. 1.0 ms^-1
D. 1.5 ms^-1
The answer is A and it can be calculated from the equation A1v1=A2v2+A3v3.
It is very clear for me to see the correct answer by calculating it. It still, however, remains a mystery to me that why the given condition of the velocity of the liquid in Y would be 0.6 ms^-1 !!!!?
I think the velocities of the liquid in the two pipes Y and Z would be the same, just like when they are combined into one....
No matter if you can settled my problem, I appreciate you a lot for thinking my question.
更新1:
Chi-Wing: You haven't taken a deep notice at my question. I think velocity of the liquid flowing through the pipes Y and Z should be the same and satisfy the principle of conservation of mass flow rate, i.e. 9.6/(15+6) ms^-1
