## Essential University Physics: Volume 1 (3rd Edition)

$\rho = 6 \times 10^2 \ kg/m^2$
We simplify the equation for flow speed in order to isolate density. Doing this, we obtain: $\rho = \frac{2\Delta P}{((\frac{A_1}{A_2})^2 - 1)v^2}$ We know that $\frac{A_1}{A_2}=4$. Plugging this in, the pressure as $16\times 10^3$, and the velocity as 1.9 meters per second, we obtain: $\rho = 6 \times 10^2 \ kg/m^2$