P10

• Newtons 2nd law 


  The acceleration of an object is directly proportional to the resultant force acting on it, and inversely proportional to the mass of the object
• Weight 


  The force that acts on an object due to its gravity, measured in Newtons
• Describe Terminal velocity 


  When the resistive forces and driving forces acting on an object become equal , the object will no longer be accelerating and will instead be moving at constant speed
• Thinking distance 


  The distance travelled by a vehicle while the driver is reacting to a hazard
• Factors affecting thinking distance


  • Alcohol
  • Drugs
  • Fatigue
  • Distractions
  • Speed
• Braking distance 


  The distance travelled by a vehicle once the brakes have been applied
• Factors affecting braking distance


  • Worn brakes
  • Worn tyres
  • Wet or icy roads
  • Speed
• Stopping distance 


  Total distance travelled by a vehicle from the driver spotting a hazard to coming to a complete stop.
• Momentum


  Vector quantity that combines the mass and velocity of an object
• Law of conservation of momentum


  The momentum before a collision or explosion must remain equal to momentum afterwards
• Car safety features


  Used to ensure the time taken for a persons change in momentum is as long as possible

  • Crumple zones
  • Airbags
  • Seatbelts
• Spring constant 


  Describes the stiffness of a material
• For an object to obey Hooke's law, the extension of the material must be directly proportional to the force applied. This is shown by a straight line on a graph
• Limit of proportionality 


  Refers to the point beyond which Hooke's law is no longer true when stretching a material