The height-time curve for the sedimentation of a suspension in a vertical cylindrical vessel is shown below. The initial solids concentration of the suspension is100 kg/m'. 5 75 8 50 100 200 300 400 500 Time (s) Calculate (i) the velocity of the interface between clear liquid and suspension of concentration 100 kg/m' (ii) the time from the start of the test at which the suspension of concentration 200 kg/m' is in contact with the clear liquid (iii) the velocity at which a layer of concentration 200 kg/m' propagates upwards from the base of the vessel (iv) the concentration of the final sediment. [12] Height of interface between suspension and clear liquid (cm)