Terms

Center of Mass
The point at which a given net force acting on the system will produce the same
acceleration as if all the mass were concentrated at that point.

Impulse
A force applied over a period of time. See definition of impulse.

Momentum
The product of an object's mass and velocity. See definition of momentum.

Conservation of Momentum
The principle stating that for any system with no external forces acting on it,
momentum will be conserved.
Formulae
Position of the center of mass of a system of particles
 x_{cm} = m_{n}x_{n} 
Velocity of the center of mass of a system of particles
 v_{cm} = m_{n}v_{n} 
Acceleration of the center of mass of a system of particles
 a_{cm} = m_{n}a_{n} 
Acceleration of the center of mass of a system of particles given an external
force
 F_{ext} = Ma_{cm} 
Definition of Impulse
 J = FΔt 
Change in velocity caused by an impulse
 J = mv_{f}  mv_{o} 
Definition of momentum
 p = mv 
Relation between force and momentum
 = F 
ImpulseMomentum Theorem
 J = Δp 
Definition of the linear momentum of a system of particles
 P = Mv_{cm} 