Momentum (2/2)

• What is the relationship between force and momentum as discussed in the video?

  Forces can speed up or slow down an object, changing its momentum.
• How is momentum calculated?

  Momentum is equal to mass times velocity.
• If a two-kilogram particle is traveling at five meters per second, what is its momentum?

  The momentum is 10 kilogram meters per second.
• What happens to the momentum of an object when a force is applied in the same direction as its motion?

  The momentum of the object increases as its velocity increases.
• What is the new momentum of a two-kilogram particle traveling at eight meters per second?

  The new momentum is 16 kilogram meters per second.
• How do you calculate the force required to change momentum?

  Force is equal to the change in momentum divided by the time over which the change took place.
• If the change in momentum is 6 and the time is 0.5 seconds, what is the force applied?

  The force applied is 12 newtons.
• What does the equation mv represent in the context of momentum?

  mv represents the final momentum of an object.
• How do you calculate the force required to accelerate a 600-gram ball from rest to 14 meters per second in 0.1 seconds?

  You plug the values into the equation and find the force to be 84 newtons.
• What is the initial velocity of the ball in the example given?

  The initial velocity is zero since the ball starts at rest.
• Why is it important to spread the change in momentum over a longer period of time during car crashes?

  It reduces the force experienced by people inside the car, lowering the risk of injury.
• What are some safety features in cars designed to reduce injury during crashes?

  Crumple zones, seat belts, and airbags are designed to reduce injury.
• What are the functions of crumple zones in cars?

  • Crumple zones absorb impact energy.
  • They increase the time taken for the car to lose momentum.
  • They help reduce the force experienced by passengers.
• What are the functions of seat belts in cars?

  • Prevent passengers from being ejected from the car.
  • They are slightly stretchy to slow down passengers more gradually.
• How do airbags contribute to passenger safety in a car crash?

  • Airbags are compressible like a pillow.
  • They help to slow down the passenger's momentum more gradually.
• What is the key principle behind safety systems like helmets and crash mats?

  • They increase the time taken for momentum to be lost.
  • This results in a lower force acting on the person, reducing the risk of harm.
• What is the final force calculated for the 600-gram ball accelerated to 14 meters per second?

  The final force is 84 newtons.
• What happens to the momentum of a person in a car during a collision with a brick wall?

  The momentum decreases to zero almost instantly, causing a large force on the person.
• How do safety features in cars work together to protect passengers during a crash?

  They all aim to increase the time over which momentum is lost, reducing the force experienced.
• What is the main takeaway from the video regarding forces and momentum?

  Forces can change an object's momentum, and safety features help manage this change to reduce injury.