Conservation of Momentum

• What is momentum?

  A property of all moving objects
• How is momentum calculated?

  Mass multiplied by velocity
• What is the momentum of a 4500 kg dinosaur moving at 12 m/s?

  54000 kg m/s
• What is the momentum of a 1200 kg car traveling at 25 m/s?

  30000 kg m/s
• What type of quantity is momentum?

  A vector quantity
• If the dinosaur has positive momentum, what is the car's momentum if it moves in the opposite direction?

  Negative momentum
• What does the conservation of momentum principle state?

  Total momentum before equals total after
• How do you find the total momentum before a collision?

  Add the momentums of both objects
• What is the total momentum of a dinosaur with 54000 kg m/s and a car with -30000 kg m/s?

  24000 kg m/s
• What does a positive total momentum indicate about direction?

  Movement to the right
• How do you calculate the shared velocity after a collision?

  Velocity equals momentum divided by mass
• What is the combined mass of a 4500 kg dinosaur and a 1200 kg car?

  5700 kg
• What is the shared velocity of the dinosaur and car after collision with 24000 kg m/s momentum?

  1. 4 m/s to the right
• What happens to momentum when stationary objects are involved?

  Total momentum remains zero
• What is the initial momentum of a stationary gun?

  Zero
• What happens to the gun's momentum when it fires a bullet?

  Gun recoils with equal momentum
• How do you calculate the bullet's momentum if it has a mass of 5 grams and velocity of 120 m/s?

  0.6 kg m/s
• How do you express the gun's momentum if its mass is 2 kg and velocity is unknown?

  2v
• What equation represents the conservation of momentum for the gun and bullet?

  2v + 0.6 = 0
• How do you find the gun's recoil velocity from the equation 2v + 0.6 = 0?

  v = -0.3 m/s
• What does a negative recoil velocity indicate?

  Movement in the opposite direction
• What is the symbol for momentum?

  p
• How can the momentum equation be expressed?

  p = mv
• What are the key concepts of momentum discussed in the video?

  • Momentum is mass times velocity
  • Momentum is a vector quantity
  • Conservation of momentum principle
  • Total momentum before equals total after
  • Momentum can be zero for stationary objects
• What are the steps to calculate the recoil velocity of a gun after firing a bullet?

  1. Calculate bullet's momentum
  2. Set gun's momentum + bullet's momentum = 0
  3. Rearrange to find gun's velocity