Momentum

• What is the momentum of an object that is not moving?

  The momentum is zero.
• What is the equation used to calculate momentum?

  Momentum equals mass multiplied by velocity.
• What is the unit of momentum?

  The unit of momentum is kilogram m/s.
• If a car has a mass of 1,000 kg and is not moving, what is its momentum?

  The momentum is zero.
• Calculate the momentum of a car with a mass of 1,000 kg moving at 20 m/s.

  The momentum is $20,000 \text{ kg m/s}$.
• What is the principle of conservation of momentum?


  • In a closed system, the total momentum before an event equals the total momentum after the event.
• What happens to the momentum of a van and a stationary car during a collision?

  The total momentum before the collision equals the total momentum after the collision.
• In the example of the van and the stationary car, what happens to their velocities after the collision?

  Both the van and the car move together at a lower velocity than the initial velocity of the van.
• What is the total momentum of a cannon and cannonball before firing?

  The total momentum before firing equals zero.
• What happens to the momentum of the cannon and cannonball after the cannon fires?

  The momentum of the cannonball moving forward equals the momentum of the cannon moving backward, resulting in a total momentum of zero.
• What can you conclude about momentum before and after firing a cannon?

  • Momentum before firing is zero.
  • Momentum after firing is also zero.
  • Momentum is conserved.