A small horizontal hatch of area 0.040 m2 is 3.0 m below the surface of a lake. The water density is 1000 kg/m3. The air pressure inside the hatch equals atmospheric pressure above the lake. Take g=10 N/kgg=10\ \mathrm{N/kg}g=10 N/kg. Use p=hρgp=h\rho gp=hρg. What is the resultant force due to pressure on the hatch?
120 N120\ \mathrm{N}120 N
4000 N4000\ \mathrm{N}4000 N
5200 N5200\ \mathrm{N}5200 N
1200 N1200\ \mathrm{N}1200 N
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.