设该圆柱体的底面积为S、高为h、密度为p。则:
(1)该圆柱体的重力G=mg=pvg=pshg
(2)圆柱体C在水中受到的浮力F浮=p水s(2/3)hg
(3)A点受到的拉力FA=pshg-p水s(2/3)hg=shg[p-2/3(p水)]
(4)B点受到的拉力FB=3FA=shg(3p-2p水)
(5)因为圆柱体C在水中受到的压强为800Pa,则有:p水g(2/3)h=800,解得h=0.12m
(6)因为圆柱体D对地面的压强为600Pa,则有:PB=F'/S
即:[pshg-shg(3p-2p水)]/S=600
代入h=0.12m,解得:p=7.5x10^3kg/m^3