Question

The rate mass of a fluid is 12 grams/s, is flowing in a tube at 0.9 m/s and it has a density of 1.7 grams/m3. What is the diameter of the tube?

Answer 1

$$\frac{dm}{dt}=Av\rho \\\frac{dm}{dt}=0.25\pi d^2v\rho \\12=0.25\pi d^2(0.9)(1.7)\\d=3.16\ m$$