Momentum (Higher)

• State the equation used to calculate an objects momentum?

  Momentum = Mass × Velocity
• What is the unit of momentum?

  kg m/s
• In a closed system, what can be said about the momentum before and after a collison?    

  The total momentum before is equal to the total momentum afterwards.
• State the equation that links momentum, force and time.

  Force × Time = Change in Momentum
• What quantity is equal to the force experienced in a collison?

  Rate of change in momentum
• If an object's change in momentum is fixed, what is the only way to reduce the force that the object experiences.

  Increases the length of time over which the change of momentum occurs.
• Explain how a seatbelt improves a passenger's safety during a collison.   

  Passenger must decelerate from the vehicle's velocity at impact to zero, meaning they undergo a fixed change of momentum

  The force they experience is equal to the rate of change of momentum

  Seatbelts increase the time over which the force is applied, reducing the rate of change of momentum and therefore reducing the force experienced.