A U-tube is partly filled with mercury. Water is then poured on top of the mercury on the left side of the tube. The final mercury levels on both sides are shown in the photograph. The surface of the water is not shown in the photograph. The major tick marks in the photograph is in cm. Determine the height of the water column, hw, in cm. water=1000 kg/m3 , and Hg=13,600 kg/m3