Forces

• Contact forces are forces that act between objects that are in physical contact e.g. friction or push 
• Non-contact forces are forces that act at a distance e.g. weight or magnetism 
• Contact Forces 

  Friction  

  Push  

  Pull  

   Thrust 

  Air resistance (drag)  

  Water resistance (drag) 

  Up-thrust 

  Tension  

  Lift  

  Normal contact force 
• Non-contact forces 

  Gravitational forces 

  Magnetic forces 

  Weight  

  Electro-static 
• A force is an interaction between two objects that accelerates those objects. We measure forces in Newton (N). 
• Forces can change: the speed of an object, the direction that an object is moving in, the shape of an object 
• The direction of the arrows show the direction of each force
• The length of each arrow is proportional to the size of the force