A bullet of mass [tex]m_1[/tex] strikes a pendulum of mass [tex]m_2[/tex] suspended from a pivot by a string of length [tex]L[/tex] with a horizontal velocity [tex]v_0[/tex]. The collision is perfectly inelastic and the bullet sticks to the bob. Find the minimum velocity [tex]v_0[/tex] such that the bob (with the bullet inside) completes a circular vertical loop.(adsbygoogle = window.adsbygoogle || []).push({});

What did I do wrong:

Using conservation of momentum, we have

[tex]m_1 v_0 = \left(m_1+m_2\right) v_n.[/tex]

Then

[tex]v_n=\frac{m_1 v_0}{m_1+m_2}[/tex]

and

[tex]0=v_n^2+2a dx.[/tex]

Then

[tex]v_n^2=-2 \int_0^\pi -g \sin \theta L d \theta?[/tex]

I think that's where I screwed up?

If I follow my wrong steps, I end up with

[tex]v_0=\left(m_1+m_2\right)2 \sqrt{Lg}/m_1,[/tex]

but that's not the answer.

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# Homework Help: 2008 Fnet=ma Exam: Bullet and Bob

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