If you have have double pendulum of two rods where the rods moves with the same frequency w at the equilibrium position and at the eq. position you hit the lower rod at a distance d from the point that connects the rods. The hit results in a motion where the upper rod moves with frequency w and the lower rod with frequency -w. If the rods lengths are l and their masses m what are the the distance d.(adsbygoogle = window.adsbygoogle || []).push({});

I have no problem to find the equations of motion for the ordinary double pendulum. With the hit i think it gets something like

Lagrange equations = F

Where F is different for theta1 and theta2.

If you find these equations you can solve for which d the resulting motion is w for the upper rod and -w for the lower rod, right?

But how do you write F?

Thank you

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# Double pendulum

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