A rod AB of length $L$ and mass $M$ is hinged at point A . A small bullet of mass B hits the rod with velocity $v$ perpendicular to AB at B. The bullet gets embedded in the rod . Find the angular velocity of the system just after the impact?
We can do this in many ways but each time I get a different answer I try to apply first angular momentum conservation about A of the system then linear momentum conservation but only the answer with angular momentum conservation equal the answer not the other.
So why can't we use linear momentum conservation here that is after impact assume it to be total mass of the rod and bullet times velocity of centre of mass and then multiply by distance from A to find angular velocity which is apparently wrong so why is it so ?