Mechanics

• What is a scalar quantity?


  A quantity that only has magnitude
• What is a vector quantity?


  One with both magnitude and direction
• How can a vector quantity be drawn?

  Drawn as an arrow with an associated direction and magnitude(length of the arrow)
• Is a force a vector or scalar quantity?

  Vector
• What does the gradient of a distance time graph represent?

  The velocity.
• What does the gradient of a velocity time graph represent?

  Acceleration
• What does the area under a velocity time graph represent

  Displacement
• How can the accuracy of an interactive model be improved?

  Decreasing the time interval will increase the accuracy
• What is a vehicles stopping distance?

  The thinking distance + the braking distance
• If the vehicles speed is increased, what can be said about the Stopping distance?

  increased
• What are the typical range of human reaction times?

  0.2-0.9 seconds
• Describe the energy transfers that take place when a car applies its brakes

  Work done by the friction force between the brakes and the wheels

  Kinetic energy of the wheels is converted to heat and dissipated to the surrounding through brake discs
• What is the law of conservation of momentum?


  The total momentum before is equal to the total momentum afterwards, given no external forces act
• What is the equation for momentum?

  P=mv
• What is the unit for momentum?

  $Kgms^-1$
• Is momentum scalar or vector?

  Vector