The problem is:(adsbygoogle = window.adsbygoogle || []).push({});

A uniform thin rod of length = .5m and mass M = 4.0kg can rotate in a horizontal plane about a vertical axis through its center (I = ML^2/12). The rod is at rest when a bullet of mass m = 3.0g traveling in the horizontal plance of the rod is fired into one end of the rod. As viewed from above, the direction fo the bullets velocity makes an angle of theta=60 with the rod. If the bullet lodges into the rod and the angular velocity of the rod is 10rad/s immediately after the collision, what is the bullet's speed just before impact?

This is a review question for a test I have monday, the answer is1290m/s, but I cant get that.

Here's what I did (which is obviously incorrect):

I = (1/12)ML^2 + m(L/2)^2

conservation of momentum????

mv = Iw

v = Iw/m

= (1/12)ML^2 + m(L/2)^2 / m

= wrong.

Is conservation of momentum the right tool to be using to solve this? ...how does theta play into it? Any tips will be *greatly* appreciated.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Is this conservation of momentum?

**Physics Forums | Science Articles, Homework Help, Discussion**