A simple model of the atmosphere assumes that the air has the same density at all heights.
Atmospheric pressure at sea level = 1.0 × 105 Pa
Density of air in the model = 1.2 kg/m3
Gravitational field strength g=10 N/kgg = 10\ \text{N/kg}g=10 N/kg
Use the equation: pressure=height of column×density×g\text{pressure} = \text{height of column} \times \text{density} \times gpressure=height of column×density×g
Use the model to calculate the height of the atmosphere.
The top of Mount Everest is 8850 m above sea level. The atmospheric pressure there is about 3.3 × 104 Pa.
Explain how this shows that the simple model is not correct.
Explain why the atmospheric pressure at the top of Mount Everest is lower than at sea level.
Use the model to calculate the difference in atmospheric pressure between the bottom and the top of a building that is 300 m tall.
50 exam-style questions on OCR GCSE Physics 1.3 Pressure, covering 1.3.1 Molecular motion, temperature and gas pressure, 1.3.2 Gas pressure at constant volume, 1.3.3 Compressing and expanding gases, 1.3.4 Gas volume and pressure at constant temperature, 1.3.5 Doing work on a gas, 1.3.6 The Earth's atmosphere and atmospheric pressure, 1.3.7 Atmospheric pressure and height, 1.3.8 Floating and sinking, 1.3.9 Pressure in liquids and upthrust, and 1.3.10 Pressure differences with depth. Each one has a worked solution and a mark scheme showing where the marks go.