Momentum (HT only)

• What is momentum a measure of?

  How hard it is to stop an object
• How is momentum calculated?

  Using the equation: momentum = mass x velocity
• What are the units for momentum?

  kilogram meters per second (kg m/s)
• What happens to momentum when two objects move in opposite directions?

  One will have positive momentum, the other negative
• What occurs when a force acts on a moving object?

  A change in momentum occurs
• What is the equation for force in relation to momentum?

  Force = change in momentum / time
• What does the equation F = m∆v/∆t represent?

  Force equals change in momentum over time
• What is the relationship between force and time in momentum change?

  Force equals change in momentum divided by time
• What are safety features that help reduce force during impacts?

  • Airbags
  • Seat belts
  • Gymnasium crash mats
  • Cycle helmets
• How does a cycle helmet help during an impact?

  It increases the time taken for a collision
• What happens to the force exerted on the head during an impact with a helmet?

  The force exerted is smaller due to increased time
• What is the effect of increasing the time it takes for a collision to happen?

  It reduces the force experienced during the impact
• How does the size of the head affect the force during an impact?

  A smaller head size results in less force exerted
• What is the relationship between the force exerted and the size of the deceleration?

  Smaller deceleration results in smaller force