A reversed phase HPLC separation is performed with a C18 column using H2O methanol 60:40%v/v as mobile phase. Dimensions of the column are given: 150mm (length) and 4.6mm (diameter). The particle size of the packing material is 5m(dp). The analyst switched to another C18 column with column dimensions of 100 mm (length) and 4.6mm (diameter) with a 3.5m(dp) particle size packing. The flow rate and mobile phase composition remained the same. (i) Predict the effect of changing to a column with 3.5m particle size packing, in terms of the effect on the run-time. (ii) Estimate the % change in the pressure, given P=kdp2