A liquid exits a tube with speed $v$, which is determined by the pressure difference $\Delta P$ and the liquid density $\rho$. The relationship is $v = k\left(\frac{\Delta P}{\rho}\right)^n$, where $k$ is a constant with no units. What is the value of $n$?
- A$\frac{1}{2}$
- B$1$
- C$\frac{3}{2}$
- D$2$