- #1

vladimir69

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## Homework Statement

A rod of length L and mass M is suspended vertically from a pivot (and is stationary). A ball traveling horizontally at speed v and mass m sticks to the rod at a distance L/2 from the pivot. What is the minimum speed v required so that the rod will undergo a full rotation around its pivot (as opposed to just being a pendulum).

## Homework Equations

L=Iw

L=rmv

## The Attempt at a Solution

I haven't had much luck with this chapter on rotation.

I said that initial momentum = final momentum

so

[tex]L_{0}=L[/tex]

[tex]L_{0}=\frac{1}{2}mv[/tex]

[tex]L=(\frac{1}{3}ML^2+\frac{1}{4}mL^2)\omega[/tex]

but equating the 2 is nonsense to me because you got omega and v to mess things up. I would imagine the result to be a function of m, M and L but no idea how that pops out, given that those are pretty much the only equations given in the entire chapter (gyro precession equation is the other equation)

Thanks for any assistance