- Conservation of Momentum
- The total momentum of a closed system is constant (i.e., momentum is conserved).
- Momentum is a vector quantity, so you need to pay attention to direction.
- Momentums pointing in a convenient direction should be positive.
- Momentums pointing opposite this should be negative.
- Momentums pointing in arbitrary directions are dealt with in another section of this book.
- The law of conservation of momentum is logically equivalent to Newton's third law of motion (the action-reaction law).
p = mv
|2nd law||force law
F = ma
J = Δp
F1 = −F2
|conservation of momentum
∑p = ∑p0