# Continuity / conservation of mass

Two different incompressible fluids a and b flow into a chamber through two circular ports of area 0.1 and 0.2 m2 respectively.

• Fluid a is of density 1,200 kgm−3 and flows directly into the chamber at a speed of 2 ms−1.
• Fluid b has a density of 1,500 kgm−3 and has a velocity normal to the surface of the chamber inlet port surface of 3 ms−1.
• The chamber has a single outlet port of area 0.3 m2.

What is the density and the speed of the mixture coming out of the outlet?

The answer in the back of the textbook says the correct answer is 2.6 m/s for the velocity and 1461 kg/m3 for the density. Does anyone know why my numbers are slightly off, is it possibly due to the fact that fluid B enters normal to the surface. I have attached the question below.

Thanks in advance for any help

• plz add "homework" tag Feb 19 at 17:44

$$\gamma_c = \dfrac{(1200*0.1*2)+(1500*0.2*3)}{(0.3*2.6)} = 1461(.54)$$