Contact and Non Contact Forces

• Non-contact forces

  • Gravitational force, magnetic force, electrostatic force
• Gravitational force


  Force of attraction between any two objects that have mass
• Contact forces


  Require the two objects to be physically touching
• Definition of force

  A force is a pull that acts on an object due to its interaction with another object. Force is measured in newtons
• Contact forces

  • Friction, air resistance, tension, normal contact force
• Electrostatic force


  Between charged objects and can be attractive or repulsive
• Types of forces

  • Contact forces
  • Non-contact forces
• Magnetic force

  Can be attractive or repulsive depending on the poles of the magnets
• Non-contact forces


  Do not require the two objects to be physically touching
• Force measurement example


  • When a hand pushes a box, it exerts a force like five newtons
• Forces


  Classified as vector quantities because they have both magnitude and direction
• Strength of non-contact forces

  Decreases as the objects get further apart