Seawater is passed through a column containing a bed of resin beads.
- Density of seawater $=1025 \: \text{ kg m}^{-3}$
- Density of resin beads $=1330 \text{ kg m}^{-3}$
- Diameter of resin beads $=50 \: \mu \text{ m}$
- Void fraction of the bed at the onset of fluidization $=0.4$
- Acceleration due to gravity $=9.81\text{ m s}^{-2}$
The pressure drop per unit length of the bed at the onset of fluidization is ___________$Pa \: \text{ m}^{-1}$ (round off to nearest integer).