Momentum

• All moving objects have momentum
• Non-moving objects have a momentum of 0
• momentum = mass x velocity
• unit of momentum is kg m/s
• Conservation of momentum

  In a closed system, the total momentum before an event is equal to the total momentum after an event
• if a van and a car collide,the total velocity of the van and the car together is now the same as the initial momentum of the van by itself. The total momentum before the collision is the same as the total momentum after.
• If we had a cannon-

  • Before the cannon fires both the cannon and cannonball are not moving
  • The total momentum before firing = 0
  • When the cannon fires, the cannonball has momentum towards and the cannon recoils (has momentum) backwards.
  • backward momentum = forward momentum
  • Total momentum is still 0