Physics forces and motion

• 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.
• How do you 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 is the momentum of the stationary car before the collision?

  The momentum is zero.
• What happens to the momentum of a cannon and cannonball before and after firing?

  The total momentum before firing is zero, and the total momentum after firing is also zero.
• How does the momentum of the cannonball and the cannon relate after the cannon fires?

  The backward momentum of the cannon equals the forward momentum of the cannonball.
• What is the main topic of the video discussed in the study material?

  Momentum calculations involving collisions
• What is the equation used to calculate momentum?


  Momentum equals mass multiplied by velocity
• What does it mean for momentum to be conserved in a closed system?

  The total momentum before an event is equal to the total momentum after the event
• How do you calculate the total momentum before a collision?

  • Calculate the momentum of each object using the formula: momentum = mass × velocity
  • Sum the momentum of all objects involved in the collision
• If a van with a mass of 2,000 kg is traveling at 30 m/s, what is its momentum?


  The momentum is $60,000 \text{ kg m/s}$
• What is the momentum of a stationary car?


  The momentum of a stationary car is zero
• What is the total momentum of both the van and the car before the collision in the example given?


  The total momentum is $60,000 \text{ kg m/s}$
• How do you calculate the velocity of the van and the car together after the collision?


  Velocity equals momentum divided by mass
• What is the combined mass of the van and the car after the collision in the first example?


  The combined mass is $2,800 \text{ kg}$
• What is the velocity of the van and the car combined after the collision in the first example?


  The velocity is $21.4 \text{ m/s}$
• How do you approach a momentum calculation problem involving a collision?


  1. Identify the masses and velocities of the objects involved.
  2. Calculate the momentum of each object before the collision.
  3. Sum the momenta to find the total momentum before the collision.
  4. Use the conservation of momentum to find the total momentum after the collision.
  5. Calculate the combined velocity using the total momentum and combined mass.
• If a van with a mass of 1,400 kg is traveling at 20 m/s, what is its momentum?

  The momentum is $28,000 \text{ kg m/s}$
• What is the combined mass of the van and the car after the collision in the second example?


  The combined mass is $2,400 \text{ kg}$
• What is the velocity of the van and the car combined after the collision in the second example?

  The velocity is $11.67 \text{ m/s}$