Conservation of Momentum. If nonimpulsive forces or no
impulsive forces act on the body in a particular direction, or if the motions
of several bodies are involved in the problem, then consider applying the
conservation of linear or angular momentum for the solution.
Investigation of the free-body diagram (or the impulse diagram) will aid
in determining the directions along which the impulsive forces are zero, or
axes about which the impulsive forces create zero angular impulse. For
these cases,