1. A block of wood weighing 105 N and of specific gravity 0.75 is tied by a string to the bottom of a tank of water in order to have the block totally immersed. What is the tension in the string? 2. A vertical test-tube has 2 cm. of oil (density= 0.80 g/cu. cm.) floating on 8 cm. of water. What is the pressure at the bottom of the tube due to the fluid in it? 3. A standing woman whose head is 35 cm. above her heart bends over so that her head is 35 cm. below her heart. What is the change (in torr) in the blood pressure in her head? 4. In which liquid will an iron ball weighing 20 N weigh more in water or in alchohol? By how much? Please help my friend? Even if you don't want to answer some of them, will you please help us? Oh, I'm new here but not new at lurking..