Compressible Fluids and Objects
The atmosphere's density depends upon altitude. As an airship rises in the atmosphere, its buoyancy decreases as the density of the surrounding air decreases. In contrast, as a submarine expels water from its buoyancy tanks, it rises because its volume is constant (the volume of water it displaces if it is fully submerged) while its mass is decreased.
Read more about this topic: Buoyancy
Famous quotes containing the word objects:
“It is an inexpressible Pleasure to know a little of the World, and be of no Character or Significancy in it. To be ever unconcerned, and ever looking on new Objects with an endless Curiosity, is a Delight known only to those who are turned for Speculation: Nay, they who enjoy it, must value things only as they are the Objects of Speculation, without drawing any worldly Advantage to themselves from them, but just as they are what contribute to their Amusement, or the Improvement of the Mind.”
—Richard Steele (1672–1729)