A solid rectangular block is held at rest fully under water. The top and bottom faces of the block are horizontal.
The top face of the block is 0.20 m below the surface of the water. The block is 0.30 m tall.
The top face and the bottom face each have an area of 0.050 m2.
The density of water is 1000 kg/m3. The gravitational field strength, ggg, is 10 N/kg.
Calculate the pressure due to the water on the top face of the block.
Use the equation
P=h×ρ×gP = h \times \rho \times gP=h×ρ×g
Calculate the pressure due to the water on the bottom face of the block.
Calculate the upthrust on the block.
Show that the upthrust is equal to the weight of the water displaced by the block.
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.