Sea Level Conditions of the U.S. Standard Atmosphere Property Symbol SI Temperature T 15 °C Pressure P 101.3 kPa (abs) Density ρ 1.225 kg/m³ Specific weight γ 12.01 N/m³ Viscosity μ 1.789 x 10¯⁵ kg/(m • s) (Pa • s) 6. The Principle of Buoyancy Archimedes of Syracuse (circa 287 -212 BC) established the principle of buoyancy. Draw a picture of something floating. 7. The Principle Applied: Setting Sail on the Sky Sea In 1766 Henry Cavendish discovered Hydrogen. P.M. HB In 1782, the first artificial lift was demonstrated by a balloon filled with hydrogen. -In 1783, the Montgolfier brothers gave the first public demonstration. 8. Hot Air Balloon 8. The Relative Densities Picture showing the density of Water, Steel block, and Mercury. To go up in a hot air balloon: Heat the air. To go down: Allow to cool. To go down: Release some hot air. Turn off fans
