Fluid Mechanics Viscosity Question 115

Question: An L-shaped tube with a small orifice is held in a water stream as shown in fig. The upper end of the tube is 10.6 cm above the surface of water. What will be the height of the jet of water coming from the orifice? Velocity of water stream is 2.45 m/s

Options:

A) $ 27.8,m{{s}^{-1}} $

B) $ 41.0,m{{s}^{-1}} $

C) $ 9.6,m{{s}^{-1}} $

D)$ 19.7,m{{s}^{-1}} $

Show Answer

Answer:

Correct Answer: B

Solution:

According to Bernoulli’s theorem,$ P_{B}+h\rho g=P_{A}+\frac{1}{2}\rho v_{A}^{2} $ $ (\text{As }v_{A}»v_{B}) $ $ 3.10P+53\times 660\times 10=P+\frac{1}{2}\times 660v_{A}^{2} $ Þ $ 2.1\times 1.01\times 10^{5}+3.498\times 10^{5} $ $ =\frac{1}{2}\times 660\times v_{A}^{2} $ Þ $ 5.619\times 10^{5}=\frac{1}{2}\times 660\times v_{A}^{2} $ \ $ v_{A}=\sqrt{\frac{2\times 5.619\times 10^{5}}{660}} $ = 41 m/s