A scientific research team is investigating a sealed metal container resting on the bed of a deep freshwater lake. The hatch on top of the container has dimensions of 1.5 m1.5\text{ m}1.5 m by 1.2 m1.2\text{ m}1.2 m. The hatch is located at a depth of 24 m24\text{ m}24 m below the surface of the lake. The atmospheric pressure is 1.0×105 Pa1.0 \times 10^5\text{ Pa}1.0×105 Pa, and the density of fresh water is 1000 kg/m31000\text{ kg/m}^31000 kg/m3.
Calculate: (i) the pressure on the hatch due to the fresh water, (ii) the total pressure on the hatch, (iii) the downward force that this total pressure produces on the hatch.
The actual force needed to pull the hatch open is not equal to the value calculated in (a)(iii). Suggest two reasons for this. (Assume g=9.8 m/s2g = 9.8\text{ m/s}^2g=9.8 m/s2 or g=10 m/s2g = 10\text{ m/s}^2g=10 m/s2)
188 exam-style questions on CIE IGCSE Physics Pressure, covering Pressure. Each one has a worked solution and a mark scheme showing where the marks go.