Question

Water flows through a rubber hose 2 cm in diameter at a velocity of 4 m/s. What must be the diameter of the nozzle in order that the water emerge at 16 m/s?

(a) 0.884 cm

(b) 0.891 cm

(c) 0.881 cm

(d) 0.894 cm

I got this question by my college director while I was bunking the class.

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

Answer 1

The correct option is (d) 0.894 cm

To elaborate: The area is proportional to the square of diameter, so:

v1d1^2 = v2d2^2

d2^2 = v1d1^2 / v2 = \(\frac{(4 \frac{m}{s})(2cm)^2}{(20 cm)^2}\)

d2 = 0.894 cm