contact and non-contact forces

• what is a force?

  a push or pull that acts on an object due to the interaction with another object
• all forces between objects are either...

  • contact forces
  • non-contact forces
• what is a contact force?

  the objects are physically touching
• what is a non-contact force?

  the objects are physically separated (e.g. a magnet)
• what are examples of contact forces?

  • friction
  • air resistance
  • tension
  • normal contact force
• what are examples of non-contact forces?

  • gravitational force
  • electrostatic force
  • magnetic force
• is force a vector or scalar quantity?


  vector
• what do we measure force in?

  newtons (N)
• what is a normal contact force?

  equal and opposite force
• non-contact forces ________ as they get further apart?


  decrease