Dragging, Floating, and Jumping
Primitive ways of flying and swimming are introduced in this chapter. Extremely small creatures can move through very viscous fluids without utilizing any special motive device (Azuma 1979). The force of gravity acting on their bodies does not prevent them from floating easily in turbulent air or water, using the “drag force,” or simply “drag.” The magnitude of drag depends on three things: effective surface area of the body, relative speed of the flow, and density of the fluid. Jumping is also easier for smaller creatures than for larger ones. Large creatures are unable to fly in air, and a fall from a high altitude to the ground or the surface of water can injure them severely. Without wings, they are confined to water or land.
KeywordsDrag Coefficient Free Fall Aerodynamic Drag Fern Spore Asiatic Clam
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