Physics · Pressure due to a fluid column, Pascal's law and its applications, effect of gravity on fluid pressure

If the air density were uniform, then the height of the atmosphere above the sea

If the air density were uniform, then the height of the atmosphere above the sea level to produce a normal atmospheric pressure of \( 1.0 \times 10^{5} \) Pa is (density of air is \( 1.3 \mathrm{kg} / \mathrm{m}^{3}, \mathrm{g}=10 \mathrm{m} / \mathrm{s}^{2} \) ):

  • A. \( 0.77 \mathrm{km} \)
  • B. 7.7 km
  • C. \( 77 \mathrm{km} \)
  • D. 0.077 km

Step-by-step solution

Using the formula for pressure due to a fluid column, P = ρgh, we solve for h: h = P/(ρg). Substituting P = 1.0 × 10^5 Pa, ρ = 1.3 kg/m^3, g = 10 m/s^2 gives h = (1.0 × 10^5) / (1.3 × 10) ≈ 7692.3 m = 7.6923 km ≈ 7.7 km.
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