The bunchberry flower has the fastest-moving parts ever observed in a plant. Ini

Question

The bunchberry flower has the fastest-moving parts ever observed in a plant. Initially, the stamens are held by the petals in a bent position, storing elastic energy like a coiled spring. When the petals release, the tips of the stamen act like medieval catapults, flipping through a 60angle in just 0.28 to launch pollen from anther sacs at their ends. The human eye just sees a burst of pollen; only high-speed photography reveals the details. As in the following figure shows, we can model the stamen tip as a 1.0--long, 9.0 rigid rod with a 9.0 anther sac at the end. Although oversimplifying, we'll assume a constant angular acceleration

Explanation / Answer

angular displacement = w0 t + 1/2 at^2 where w0=initial ang vel a=ang accel t=time we first find ang accel from ang accel = (change in ang vel)/time = 6rev/s/9s 6 rev/s = 6x2pi rad/s , a = 4.19rad/s/s the initial speed starting up is 0, so for the first 9 secs we have ang displacment =1/2(4.19rad/s/s)(9s)^2=169.7 rad in the second 9 s, the tub has a speed of 6 rev/s (=37.7rad/s, and we use this as the initial vel of the interval) we have ang displacement = 37.7rad/sx9s - 1/2(4.19rad/s/s)(9s)^2 = 339.1rad - 169.7 rad

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