Change in momentum

• What is momentum defined as?

  Momentum is a combination of mass and velocity.
• Why is momentum important in nature?

  Momentum helps explain some of the most important interactions in nature.
• What is the formula for calculating momentum?

  • Momentum = mass × velocity
• What happens when a resultant force acts on a moving object?

  There is a change in momentum.
• How do you calculate the force involved when a change in momentum occurs?

  1. Use the equation: force = mass × acceleration
  2. Acceleration can be calculated as:

  • \( \alpha = \frac{change \ in \ velocity}{time \ taken} \)

  1. Combine to get:

  • \( F = \frac{change \ in \ momentum}{time \ taken} \)
• What units are used to measure force, change in momentum, and time taken?

  Force is in newtons (N), change in momentum in kg m/s, and time in seconds (s).
• If a car has a mass of 1,500 kg and changes its velocity from 0 to 30 m/s in 20 seconds, what is the force applied?

  The force is \( F = 2,250 \ N \).
• What does Newton's third law state about collisions?

  Objects exert equal and opposite forces on each other during collisions.
• How does momentum behave in a collision?

  Each object gains the same momentum but in opposite directions.
• What are car safety features designed to do during a collision?

  • Change the shape of the car
  • Increase the time taken for the collision
  • Decrease the rate of change of momentum
  • Decrease the force of the collision on occupants
• What are crumple zones in a car?

  Crumple zones are areas designed to deform on impact.
• How do safety features like seatbelts and airbags work?

  They increase the time taken for the collision, reducing the force experienced.
• What is the relationship between force and the rate of change of momentum during a collision?

  • The force of the collision is equal to the rate of change of momentum.
  • This means that higher rates of change result in greater forces.