As a pilot is flying in level flight at 9,500 ft., the altimeter in the instrument panel is set to a pressure of 758 mm of Hg. As the aircraft travels along its route,

Question

the outside air temperature changes from 15.0°C to 45.0°C. To what pressure does the pilot need to reset the altimeter in order for the altimeter to indicate the aircraft's true altitude?

Answer 1

From the ideal gas law, P₂ /P₁ = T₂ /T₁ for the same volume and quantity of gas. P₂ = (758 mmHg) (45 +273 K) / (15 +273K) = 837 mmHg.