PHYS 1145 Lecture Notes - Lecture 7: Pressure Measurement

Given is depth of water (0.23 m), thickness of oil layer (0.27 m), specific gravity of oil (0.6). I also know gravity and density for water and the absolut pressure. But how can I know the density of the oil? Because I need that to get the total pressure, right?

The absolute pressure in water at a depth of 5m is read to be 145 kPa. Determine (a) the local atmospheric pressure, and (b) the absolute pressure at a depth of 5 m in a liquid whose specific gravity if 0.85 at the same location. (density of water is 1000 kg/m3)

Derive an expression for the buoyant force on a spherical balloon, submerged in a freshwater lake, as a function of the depth below the surface, the volume of the balloon at the surface, the pressure at the surface, and the density of the water. (Assume that the water temperature does not change with depth.)