Momentum

• What is momentum?

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

  Mass multiplied by velocity
• What is the momentum of a 4,500 kg dinosaur moving at 12 m/s?

  $54,000 \text{ kg m/s}$
• What is the momentum of a 1,200 kg car traveling at 25 m/s?

  $30,000 \text{ kg m/s}$
• What type of quantity is momentum?

  It is a vector quantity
• What does a positive momentum indicate in this context?

  Movement to the right
• What does a negative momentum indicate in this context?

  Movement to the left
• What is the conservation of momentum principle?

  Total momentum before equals total momentum 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 momentum $54,000 \text{ kg m/s}$ and a car with momentum $-30,000 \text{ kg m/s}$?


  $24,000 \text{ kg m/s}$
• What does a positive total momentum indicate after a collision?

  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 4,500 kg dinosaur and a 1,200 kg car?

  $5,700 \text{ kg}$
• What is the shared velocity of the dinosaur and car after collision?

  $4.4 \text{ m/s to the right}$
• What happens to momentum when stationary objects collide?

  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?

  $0.6 \text{ kg m/s}$
• What is the equation for the gun's momentum?

  Momentum equals mass times velocity
• How do you find the gun's recoil velocity?

  Set gun's momentum plus bullet's momentum to zero
• What is the recoil velocity of a 2 kg gun if the bullet has a momentum of 0.6 kg m/s?

  $-0.3 \text{ m/s}$
• 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 equals m times v
• 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
• 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
  • Momentum before equals momentum after
• What is momentum equal to?

  Mass times velocity
• How does applying a force affect an object's momentum?

  It changes the object's momentum
• If a 2 kg particle travels at 5 m/s, what is its momentum?

  10 kg m/s
• What happens to momentum when velocity increases?

  Momentum also increases
• What is the new momentum of a 2 kg particle traveling at 8 m/s?

  16 kg m/s
• What is the equation for calculating force based on momentum change?

  Force = change in momentum / time
• If the change in momentum is 6 kg m/s and the time is 0.5 seconds, what is the force?

  12 N
• What does mv represent in the momentum equation?

  Final momentum
• What does mu represent in the momentum equation?

  Initial momentum
• How do you calculate the force required to accelerate a 600 g ball to 14 m/s in 0.1 seconds?

  Use the momentum change equation
• What is the initial velocity of a ball that starts from rest?

  Zero
• What is the mass of a 600 g ball in kilograms?

  0.6 kg
• What is the final momentum of a 600 g ball accelerated to 14 m/s?

  8.4 kg m/s
• Why is the change in momentum significant during car crashes?

  It can cause injuries due to high force