Momentum Conservation 0 EXT 0 IXI △t The concept of momentum conservation is one of the most fundamental principles in physics This is a component (vector) equation We can apply it to any direction in which there is no external force applied You will see that we often have momentum conservation even when energy is not conserved Physics 121: Lecture 16, Pg 4Physics 121: Lecture 16, Pg 4 Momentum Conservation The concept of momentum conservation is one of the most fundamental principles in physics. This is a component (vector) equation. We can apply it to any direction in which there is no external force applied. You will see that we often have momentum conservation even when energy is not conserved. t p EXT   F = = 0   t p FEXT = 0