①p＝ρ_水gh                                             
＝1.0×10³千克/米³×9.8牛/千克×0.3米＝2.94×10³帕   
F＝p S                                                 
＝2.94×10³帕×0.02米²＝58.8牛                      
G_水＝m_水g＝2千克×9.8牛/千克＝19.6牛
F_桌＝G_水+ G_容=19.6牛+2牛=21.6 牛                       
p_桌＝F_桌/S                                           
＝21.6牛/（0.02米²）＝1080帕