Contact and Non-Contact Forces

• What is the definition of a force?

  A push or pull acting on an object
• What are the two components of a force?

  Magnitude and direction
• What is the unit of force?

  Newton
• How can forces be categorized?

  Into contact forces and non-contact forces
• What are contact forces?

  • Forces that occur when two objects interact
  • The objects are physically touching
  • Examples include tension, friction, and air resistance
• How does tension in a rope act in a tug of war?

  It pulls on the soldier
• What role does friction play when an airplane lands on water?

  It slows down the airplane
• What is air resistance?

  A contact force acting upwards on a sky diver
• What is the normal contact force?

  An upward force exerted by a surface
• How does the normal contact force relate to the weight of an object?

  It balances the downward weight force
• What are non-contact forces?

  • Forces that occur when objects are separated
  • Examples include gravitational, electrostatic, and magnetic forces
• What is gravitational force?

  Attraction between all objects
• How does gravitational force act on the International Space Station?

  It attracts the ISS to Earth
• What is electrostatic force?

  The force between two charged objects
• What happens when objects with opposite charges interact?

  They experience an electrostatic force of attraction
• What occurs when objects with the same charge interact?

  They experience an electrostatic force of repulsion
• What is magnetic force?

  The force experienced in a magnetic field