Final answer:
Atmospheric pressure decreases with altitude due to the lessening air mass above. The decline in pressure is not linear; it drops off more quickly at lower altitudes, with a dramatic drop encountered at the highest points such as peaks like Mt. Everest.
Step-by-step explanation:
As we move away from Earth, the atmospheric pressure in the various layers decreases. This decrease is due to the diminishing weight of the gases exerting pressure from above. At sea level, the pressure of the atmosphere is about 1 bar or 100 kPa, which means we have a column of air that weighs approximately 10,000 kg pressing down on each square meter. However, this pressure drops as altitude increases because there is less air mass above. For instance, at the summit of Mt. Everest, which is 8,848 meters high, the atmospheric pressure is only about 253 mm Hg.The atmosphere is made up of layers of gases that are held close to Earth by gravity. The density of these gases is highest at the surface because they are compressed by the weight of all the gases above. This means that atmospheric pressure, which is the force per unit area exerted by the weight of the air, is greatest at sea level. As you ascend into higher layers of the atmosphere, the amount of air—and consequently the pressure—declines rapidly. This decreasing pattern is not linear; pressure drops off more quickly at lower altitudes.Conclusion Ultimately, the atmospheric pressure decreases with altitude due to the reduction in the overlying air mass. This is crucial for various activities like hiking, aviation, and weather forecasting. Understanding the changes in atmospheric pressure with altitude is essential for many scientific and practical applications.