You should have noticed that the Styrofoam ball rolled slightly towards the rod and then appeared to be lifted above the pan. Which type of force explains why the rod was able to lift the Styrofoam ball?

Panel bc in fig. p2.76 is semi-circular, with the 3 meter radius and horizontal straight edge through point b. compute (a) the hydrostatic force of the water on the panel, (b) its center of pressure, and (c) the moment of this force about point b. assume atmospheric pressure on the dry side of the panel