Heat and Mass Transfer

Water flows inside a pipe of internal diameter $D = 0.025\text{ m}$ with thermal conductivity $k = 0.60\text{ W/(m}\cdot\text{K)}$. If the forced convection heat transfer coefficient is $h = 2400\text{ W/(m}^2\cdot\text{K)}$, the Nusselt number ($Nu = \frac{h D}{k}$) is ________ (answer in integer).