Change in momentum

• State an equation linking change in momentum, force and time.

  Force x Time = Change in Momentum

  F (delta) t = m (delta) v
• What quantity is equal to the force experienced in a collision?

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

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

  • 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