Scalars and Vectors

• All physical quantities can be described as either a scalar or a vector quantity
• Scalar Quantities:

  Scalar Quantities have size or a magnitude but no specific direction. Examples include :

  • Mass
  • Speed
  • Energy
  • Temperature
  • Distance
• Vector Quantities :

  Vector quantities have a size or magnitude and a specific direction . Examples include :

  • Force or weight
  • Acceleration
  • Displacement
  • Momentum
  • Velocity
• Speed has size but velocity has a size and a direction .
• Velocity is speed in a stated direction
• All vector quantities can be given positive and negative values to show their direction examples include :

  • A force of +4N may be balanced by a force acting in the opposite direction of -4N
  • A car that accelerates at a rate of 2 m/s could decelerate at - 2 m/s