There are two kinds of momentum, linear and angular. A spinning object has angular momentum; an object traveling with a velocity has linear momentum. We'll focus on linear momentum for now, and just refer to it as momentum.

The symbol for momentum is p.

Four fast facts about momentum

1. p = mv
   
   
2. Momentum is a vector, pointing in the direction of the velocity.
   
   
3. If there is no net force acting on a system, the system's momentum is conserved.
   
   
4. A net force produces a change in momentum that is equal to the force multiplied by the time interval during which the force was applied.