A double-pendulum, initially in a vertical position, is attached to a pin. The distance from the mass m (3.2 kg) at the top of the pendulum to the pin is 0.2 m, the distance from the mass m (3.2 kg) at the bottom of the pendulum to the pin is 0.4 m. A bullet of mass 0.05 kg is fired into the bottom mass at 300 m/s, 20 degrees up from the horizontal. What is the maximum angle that the pendulum reaches before it swings back?(adsbygoogle = window.adsbygoogle || []).push({});

EDIT: I forgot this info. The bullet becomes embedded in the bottom mass after it hits. And the initial ω=6 rad/s (counter-clockwise)

I'm not too sure how to approach this problem. I used the principle of Conservation of Angular Momentum and figured out ω=-2.78 rad/s after the impact. (Hpendulum + Hbullet = Htotal)

I know that ω=0 rad/s when the pendulum reaches the maximum angle. However, I'm not sure how to calculate that angle, since if ω is 0, then H=0?

I think that maybe I should use energy methods, but I'm not sure how to do so exactly.

Any help would be appreciated!

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# Homework Help: Conservation of Angular Momentum

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