If the manometer liquid is in the position indicated by $CD,$ determine the pressure difference in kPa between the center points of the two pipelines in the figure, A and $B.$ The density of the liquid in $AC$ and $DB$ is $p=700k\frac{g}{m^3}$ and that in $CD$ is $PCD=1000k\frac{g}{m^3}.$

A river flowing at $15f\frac{t}{s}$ turns and forms a $90ft$ high waterfall. Determine the speed of the water before it hits the rocks under the waterfall. $($The temperature of the flowing water is $5C).$