Grades K–2 · Organisms
Why does a maple seed spin as it falls?
A maple tree can release seeds with a thin wing attached. A winged seed may spin around and around as it falls. It looks like a tiny helicopter, but it has no engine.
In the diagramA winged seed turns as it fallsOne view of the turnTurnsFallsAir pushesupwardThe heavier seed is at one endNo engine: moving air helps slow the fall
The heavy seed sits near one end of the wing. As it falls, moving air pushes on the wing. The wing’s shape and the seed’s position help it turn.
Air pushes upward on the turning wing and slows the fall. Wind can carry the seed sideways during this slower journey. The seed still moves downward; spinning does not make it float forever.
About this explanation
Starting knowledge: Notice that air can push on a moving object.
Sources
- Lentink and colleagues, Science — Leading-edge vortices elevate lift of autorotating plant seeds