Forces and their interactions

• What is a scalar quantity?

  A quantity that only has a magnitude
• Why is a scalar quantity not direction dependent?

  It only has magnitude, not direction
• What is a vector quantity?

  A quantity that has both magnitude and direction
• How can a vector quantity be visually represented?

  As an arrow indicating magnitude and direction
• What does the length of a vector arrow represent?

  The magnitude of the vector quantity
• What does the direction of a vector arrow indicate?

  The associated direction of the vector quantity
• What is a force?

  A push or pull acting on an object
• What causes a force to act on an object?

  Interaction with another object
• What are the two categories of forces?

  Contact forces and non-contact forces
• What are examples of contact forces?

  • Friction
  • Air resistance
  • Tension
• What are examples of non-contact forces?

  • Gravitational forces
  • Electrostatic forces
  • Magnetic forces
• Is force a vector or a scalar quantity?

  Vector
• What does it mean for force to be a vector quantity?

  It has both magnitude and direction
• What are examples of vector quantities?

  • Velocity
  • Displacement
  • Force
• What are examples of scalar quantities?

  • Temperature
  • Time
  • Mass
  • Speed
  • Distance
  • Energy
• What is weight?

  The force due to gravity on an object
• What does weight depend on?

  The object's mass and gravitational field strength
• What is the formula for weight?

  Weight = mass x gravitational field strength
• What is the unit used for weight?

  The Newton (N)
• What is the unit used for gravitational field strength?

  N/kg
• What equipment measures an object's weight?

  A calibrated spring-balance or newton-meter
• What is meant by an object's centre of mass?

  The point where weight acts through
• What is the name of the single force equivalent to all other forces on an object?

  The resultant force