Contact and Non-Contact Forces

• What type of quantity is force?

  Vector quantity
• What do vector quantities have that scalar quantities do not?

  Direction
• What are examples of vector quantities?

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

  • Speed
  • Distance
  • Mass
  • Temperature
  • Time
• How are vectors typically represented?

  By arrows indicating magnitude and direction
• What is the difference between velocity and speed?

  Velocity is a vector; speed is a scalar
• Why do two aeroplanes with the same speed have different velocities?

  They are travelling in different directions
• What is a force?

  A push or pull on an object
• What are the two types of forces?

  • Contact forces
  • Non-contact forces
• What is a contact force?

  A force that requires touching objects
• What are examples of contact forces?

  • Friction
  • Air resistance
  • Tension in ropes
• What is a non-contact force?

  A force that does not require touching
• What are examples of non-contact forces?

  • Magnetic forces
  • Gravitational forces
  • Electrostatic forces
• What happens when two objects interact according to Newton's 3rd law?

  A force is produced on both objects
• What is a Newton's 3rd interaction pair?

  A pair of equal and opposite forces