Momentum problems
The momentum idea is usually used when two
objects interact, particularly collisions. The objects may start
together or may come together, and may end stuck together, or moving apart.
No matter what, the forces between those objects will not change the momentum.
The momentum diagram consists of a labeled
vector representing the momentum of the two objects before the interaction,
a labeled vector representing the total momentum (p1
plus p2) and then vectors representing the respective
momentums of the objects afterwards.
If the objects stick together, or start out
together and split up, there will be a vector for each of the two objects
.
The equation we write down from the momentum
equation is the sum of the momentums before is equal to the sum of the
momentums afterward.
pcar 1 before - pcar
2 before = pcars 1 after + pcar 2 after
If the objects do not travel in just one dimension,
we will have to write down the sum of the momentums for both the (X) and
(Y) coordiantes.
(X) p1 before - p2
before = p2 aftercos(q)
(Y)
0 = p1 after - p2 aftersin(q)