Explain why some objects fall faster than other objects,

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

Determine the net charge of the predominant form of arg at (a) ph 1.0, (b) ph 5.0, (c) ph 10.5, and (d) ph 13.5

What practical value did astronomy offer to ancient civilizations?