Which Conservation Law Do I Use for a Hanging Rod Hit by a Particle?

[zhenyazh]

hi
in rigid body questions are there cases where i should use moment conservation
and not angular moment conservation or the opposite?

when would i use which?

 

[aim1732]

Good question. Use momentum conservation only when there is no impulsive force on your assumed system, or a non-impulsive force for conservation over a long period of time.Angular momentum conservation holds as long as there is no torque about the point.

Here's then a question for you. A rod hanging from a pivot is hit with a particle(inelastically).What would you use?