Contact and Non-Contact Forces

• What is a force?

  A push or pull acting on an object
• What are the two categories of forces?

  Contact forces and non-contact forces
• What is the unit of force?

  Newton
• What defines contact forces?

  They occur when two objects are touching
• 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?

  It acts upward against the weight of an object
• How does gravitational force act between objects?

  It attracts all objects to each other
• What is electrostatic force?

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

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

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

  The force experienced by objects in a magnetic field
• What will be covered in later videos regarding magnetic force?

  More details about magnetic force
• How do contact forces differ from non-contact forces?

  • Contact forces: objects are touching
  • Non-contact forces: objects are separated