Final answer:
The outflow valve prevents outside air pressure from exceeding the cabin air pressure. Boyle's Law indicates that the volume of air in a passenger's stomach will change inversely with cabin pressure changes during a flight.
Step-by-step explanation:
After landing, the outflow valve prevents outside air pressure from exceeding cabin air pressure. In the context of an airplane's cabin, the role of the outflow valve is critical in maintaining a safe and comfortable environment for the passengers. The cabin pressure at cruising altitude in modern airplanes is designed to be lower than the atmospheric pressure at sea level but higher than the outside air pressure at high altitudes, to ensure passenger comfort and safety.
Regarding the provided information about changes in air volume, we can apply Boyle's Law, which states that the pressure of a gas is inversely proportional to its volume when temperature is constant. If a passenger has 100 cm³ of air in his stomach at sea level pressure (1.013 × 10⁵ N/m²) and the cabin pressure drops to 7.50 × 10⁴ N/m² at cruising altitude, the new volume V2 can be calculated using the formula P1V1 = P2V2, where P1 and V1 are the initial pressure and volume, and P2 is the pressure at cruising altitude.