تسجيل الدخول

تسجيل

The Buoyant Force of the Atmosphere

المؤلف:  GEORGE A. HOADLEY

المصدر:  ESSENTIALS OF PHYSICS

الجزء والصفحة:  p-168

2025-11-11

648

 A body submerged in water is buoyed upward by a vertical upward force that is equal to the weight of the displaced water. This pressure amounts to 62.5 lb. for each cubie foot of the volume of the submerged body. Since the air has weight, a body is buoyed up by it in the same way. The amount of the lifting force is as much less than that produced by water as the air is lighter than water. Air at sea level weighs 73 of the weight of water, or about 0.08 lb. per cubic foot. This means that the lifting power of the air on a spherical balloon 20 ft. in diameter is over 338 lb. at the surface of the earth. As the rarity of the air increases with the distance from the earth, the lifting power is less at high altitudes.