contact and non contact forces

• Contact forces


  Forces exerted between two objects when they are touching
• Contact forces


  • Can be a push or a pull
  • The unit of force is the newton (N)
• Reaction force


  Force exerted in the opposite direction to an action force
• Tension


  Pulling force exerted by each end of an object such as a string or rope
• Friction


  A force that opposes or prevents movement and converts kinetic energy into heat
• Air resistance


  A force of friction produced when an object moves through the air
• When a contact force acts between two objects, both objects experience the same size force, but in opposite directions
• This is Newton's Third Law of Motion
• Non-contact forces


  Forces that can act between objects without them being in contact
• Contact forces


  Forces that require physical contact between two objects
• Non-contact forces


  Forces that act between two objects that are not physically touching each other
• Magnetic force


  Force experienced by any magnetic material in a magnetic field
• Magnetic poles


  Opposite poles (N-S or S-N) attract, like poles (N-N or S-S) repel
• Electrostatic force


  Force experienced by any charged particle in an electric field
• Electrostatic charge


  Opposite charges (+ and -) attract, like charges (- and -, or + and +) repel
• Gravitational force


  Force experienced by any mass in a gravitational field
• Forces are responsible for all the interactions between particles and objects
• The unit of force is the newton (N)