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The science
Fall with quadratic drag
For a light, flat petal of mass m and face area A the drag force is ½ ρ Cd A |vrel| vrel, with vrel the velocity relative to the air. The terminal speed is vt = √(2 m g / (ρ Cd A)), about 1 m/s for a typical petal, and a fall from rest follows v = vt tanh(g t / vt).
Wind near the ground
Wind speed grows with height in the atmospheric boundary layer; a power law U(z) = U10 (z / 10 m)α is used, with a slowly varying gust factor (an Ornstein-Uhlenbeck process) and a travelling wave pattern. A petal falling for a time H / vt is carried about U H / vt downwind, so slow, light petals travel farthest.
Honest simplifications: real petals tumble and glide, so their drag coefficient and lift change with orientation; here Cd is a constant and flutter is a random sideways force. The wind field is a simple model, with no trees' wakes or turbulence spectrum.
What to try
- Still air: petals land close to the trees; compare with the landing histogram under Spring gusts.
- Heavy petals vs Tiny petals: terminal speed and distance change together.
- Raise the updraft and watch small petals stay aloft.
- The checks are run on separate headless drops, not on the petals you see.