An open water cistern has a horizontal pressure panel at its base, 2.5 m below the water surface. The water density is 1000 kg/m3. Air beneath the panel is at the same atmospheric pressure as the air above the water. Take g=10 N/kgg=10\ \mathrm{N/kg}g=10 N/kg. Use p=hρgp=h\rho gp=hρg. The resultant force on the panel is 500 N. Calculate the area of the panel.
0.010 m20.010\ \mathrm{m^2}0.010 m2
0.020 m20.020\ \mathrm{m^2}0.020 m2
0.050 m20.050\ \mathrm{m^2}0.050 m2
0.200 m20.200\ \mathrm{m^2}0.200 m2
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.