Measuring Drag on Rising Bubbles

Objects, vehicles, and organisms in fluids experience buoyancy, drag, and lift. Buoyancy is the upward force from the fluid’s weight. Drag is the resistive force that acts opposite motion. Lift is the force perpendicular to the direction of motion.

These forces matter in engineering and in the st...

Buoyancy and drag are two forces that commonly arise when considering the motion of an object through a fluid. The prediction and characterization of these forces is critical to solving many mechanical problems, such as engineering vehicles, or understanding the motion of swimming and flying organisms. As your intuition might suggest, the buoyan...