A sealed cylindrical monitoring unit has a mass of 45 kg and an external volume of 0.075 m3. It floats at rest in a liquid with 80% of its volume submerged. An instrument of mass 9.0 kg is then attached to the top of the unit. The instrument remains entirely above the surface and does not displace any liquid. The unit and instrument float at rest.
Calculate the percentage of the monitoring unit's volume that is above the liquid surface after the instrument is attached.
132 exam-style questions on Edexcel GCSE Physics 15.2 Pressure in fluids, covering 15.2.1 Atmospheric pressure and height, 15.2.2 Pressure in fluids, 15.2.3 Pressure, force and area, 15.2.4 Pressure and depth, 15.2.5 Pressure in liquids: depth and density, 15.2.6 Upthrust, and 15.2.7 Floating and sinking. Each one has a worked solution and a mark scheme showing where the marks go.