4. The rapid sand filter being designed for a certain town has the characteristics and sieve analysis shown below. Using the Rose equation, determine the headloss for the clean filter bed in a stratified condition. Depth =0.60m Filtration rate =130m3/dm2 Sand specific gravity =2.60 Shape factor =0.85 Stratified bed porosity =0.45 Water temperature =19C 5. Determine the height of the expanded bed for the sand used in Problem 4 if the backwash rate is 1,000m/d