The total drag force (in N) per unit width of the plate is ____

Question

Air ($\rho$=12 kg/m³ and kinematic viscosity, v = 2´10^-5 m²/s) with a velocity of 2m/s flows over the top surface of a flat plate of length 2.5m. If the average value of friction coefficient is $C_{r}=\frac{1.328}{\sqrt{Re_{x}}}$ the total drag force (in N) per unit width of the plate is ____