Momentum

• What is the formula for momentum?

  $p =$$mv$
• What does momentum represent in terms of units?

  Momentum is in kg m/s
• When is momentum conserved?

  In collisions without external forces
• What is the significance of momentum being a vector?

  It has both magnitude and direction
• What does Newton's Second Law state about force?

  Force equals rate of change of momentum
• What happens during hard braking?

  Large deceleration occurs
• What can large forces during braking cause?

  Injury to passengers
• What are the safety features in vehicles to reduce injury during braking?

  • Seatbelts: Prevent ejection from the vehicle
  • Crumple zones: Absorb energy during a crash
  • Airbags: Cushion impact to reduce neck injury
• How do seatbelts help during hard braking?

  They prevent ejection and reduce force
• What is the function of crumple zones in a vehicle?

  They absorb energy during a crash
• How do airbags protect passengers during a crash?

  They cushion the impact to reduce injury
• What happens to the time taken for the head to stop when airbags are deployed?

  It increases the time taken to stop
• What are the effects of large deceleration on passengers during braking?

  • Large forces felt by passengers
  • Potential for neck injuries (whiplash)
  • Increased risk of serious injuries
• What are the relationships between speed, braking force, and stopping distance?

  • Greater speed requires greater braking force
  • Greater braking force increases stopping distance
  • Increased stopping distance can lead to accidents