Question

Refer to Q6 and estimate a practical joker pinches the open end of the hose down to a diameter of 5 mm, and sprays his neighbor with it. What is the speed at which water comes out of the hose?

(a) 1690 cm/s

(b) 1660 cm/s

(c) 1698 cm/s

(d) 1668 cm/s

I have been asked this question in a national level competition.

The question is from Fluids in Motion topic in division Fluid Flow and Mixing of Bioprocess Engineering

Answer 1

Correct choice is (c) 1698 cm/s

Explanation: The flow rate (A1v1) of the water approaching the constriction must be equal to the flow rate leaving the hose (A2v2). This gives:

v2 = \(\frac{A_1 v_1}{A_2}\)

= \(\frac{(\pi)(106.1)}{(\pi)(0.5/2)^2}\)

= 1698 cm/s.