Conservation of momentum

• What is momentum defined as?

  Momentum is a combination of mass and velocity.
• Why is momentum important in nature?

  Momentum helps explain some of the most important interactions in nature.
• What is the principle of conservation of momentum?

  • Total momentum before an event equals total momentum after the event.
  • Applies in a closed system unaffected by external forces.
• What happens to momentum during collisions?

  Momentum is conserved; whatever momentum is lost by one body is gained by another.
• What is a collision?

  A collision occurs when two objects meet and interact.
• What is an explosion?

  An explosion occurs when parts of a system separate and move apart.
• How does conservation of momentum explain the recoil of a cannon?

  When a cannon is fired, the cannon ball gains forward momentum and the cannon gains backward momentum.
• What is the total momentum of a cannon and cannon ball before firing?

  The total momentum is zero because neither object is moving.
• What is the total momentum after the cannon is fired?

  The total momentum remains zero, with the cannon and cannon ball moving in opposite directions.
• How do you calculate the velocity of combined trolleys after a collision using conservation of momentum?

  1. Calculate momentum of both trolleys before collision.
  2. Use total momentum before collision to find total momentum after collision.
  3. Rearrange \( p = mv \) to find \( v \).
• What is the momentum of a 2 kg trolley moving at 3 m/s?

  The momentum is $6 \text{ kg m/s}$.
• What is the total momentum of an 8 kg trolley at rest?

  The total momentum is $0 \text{ kg m/s}$.
• What is the total momentum before a collision involving a 2 kg and an 8 kg trolley?

  The total momentum before the collision is $6 \text{ kg m/s}$.
• How do you find the velocity of the combined trolleys after a collision?

  Use the formula \( v = \frac{p}{m} \) where \( p \) is total momentum and \( m \) is total mass.
• What is the velocity of the combined trolleys if their total momentum is $6 \text{ kg m/s}$ and their mass is $10 \text{ kg}$?


  The velocity is $0.6 \text{ m/s}$.
• How do you calculate the velocity of a cannon after firing?

  Use the momentum of the cannon ball and apply conservation of momentum.
• What is the total momentum of a cannon and cannon ball before firing?

  The total momentum is $0 \text{ kg m/s}$.
• What is the momentum of a cannon ball after firing if its mass is 4.0 kg and its velocity is 120 m/s?

  The momentum is $480 \text{ kg m/s}$.
• What is the momentum of the cannon after firing if the cannon ball's momentum is $480 \text{ kg m/s}$?


  The momentum of the cannon is $-480 \text{ kg m/s}$.
• How do you find the velocity of the cannon after firing?

  Use the formula \( v = \frac{p}{m} \) where \( p \) is the cannon's momentum and \( m \) is its mass.
• What is the velocity of the cannon if its momentum is $-480 \text{ kg m/s}$ and its mass is $96 \text{ kg}$?


  The velocity is $-5.0 \text{ m/s}$.
• What type of quantity is momentum?

  Momentum is a vector quantity.
• What does a vector quantity include?

  A vector quantity has both magnitude and direction.
• How is direction represented in momentum calculations?

  Travelling east is positive, while travelling west is negative.
• What are the key concepts related to momentum?

  • Momentum is mass times velocity.
  • Conservation of momentum states total momentum before equals total momentum after.
  • Momentum is conserved in collisions and explosions.
  • Momentum is a vector quantity with magnitude and direction.