Momentum = mass × velocity
Impulse = force × time for which force acts = change in momentum
Momentum is a vector quantity (has magnitude AND direction), so if velocities are in opposite directions we must take this into account in our calculations (negative value = opposite direction).
Principle of the conservation of momentum:
- In an isolated system, momentum remains constant.
- When objects collide, momentum is conserved.
- Total momentum before the collision = Total momentum after.
- Kinetic energy can change.
- Resultant force – The change in momentum per unit time.