Fluids include both liquids and gases that can flow. Density is mass divided by volume, measured in kg/m³. Liquids and solids have densities around 1000 kg/m³. Gases have densities about 1 kg/m³, 1/1000 of water's density
Buoyant force is the upward force exerted by fluids on submerged objects. Force is always upward and equals the weight of the displaced fluid. Buoyancy results from pressure differences between top and bottom of an object
Buoyancy is the upward force exerted by fluids on submerged or floating objects. Archimedes' principle states that buoyant force equals fluid displaced by object. Objects float when their weight is balanced by fluid's upward force
Airfoils generate lift by creating pressure gradient between air above and below wing. Lift force requires fluid interaction and motion through fluid. Lift force equation: F_l = 1/2ρV²A C_l
Archimedes' principle states that buoyant force equals weight of displaced fluid. Objects can have negative buoyancy (sink), positive buoyancy (float), or neutral buoyancy. Neutral buoyancy occurs when object's density equals fluid's density
Lift-induced drag occurs when moving objects redirect airflow. Total aerodynamic force consists of lift and drag components. At practical angles of attack, lift exceeds drag