(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A thin metal bar, 2.00 m and a mass of 9.18 kg hangs vertically from a ceiling by a frictionless pivot. Suddenly it is struck 1.50 m below the ceiling by a small 3.00 kg ball, initially travelling horizontally at 10.0 m/s. The ball rebounds in the opposite direction with a speed of 6.00 m/s.

(a) Find the angular speed of the bar just after the collision. ***The answer in the textbook is 5.88 rad/s, and that makes sense to me.***

(b) During the collision, why is the angular momentum conserved but not the linear momentum?

2. Relevant equations

m*v(initial)*l = Iω + m*v(final)*l

3. The attempt at a solution

I have absolutely no idea how this is possible. I was always taught that momentum is always conserved.

**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!

# Why Isn't Linear Momentum Conserved?

Have something to add?

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