When is Translational Momentum Conserved

[Triangulum]

Homework Statement

When is Translational Momentum Conserved and when is Angular Momentum Conserved?

 

[Gear300]

When no net external force acts on the system...or a net change in the content of the system (essentially an isolated system...or closed system...I forgot the difference between the two if there is any). Think of it in terms of p = mv...changes in p may occur from changes in m (mass) or v (velocity). The same applies to angular momentum.