Contact and non contact forces

• What are the two types of forces discussed in the video?

  Contact forces and non-contact forces
• How can we describe a force?

  A push or pull acting on an object
• In what unit do we measure force?

  Newtons
• What does a force of five newtons indicate?

  Magnitude of the force exerted
• Why are forces classified as vector quantities?

  They have both magnitude and direction
• What is the key difference between contact and non-contact forces?

  Contact forces require physical touching
• Give an example of a contact force.

  Friction between a board and sand
• What is air resistance classified as?

  A contact force
• What is tension in terms of forces?

  The pulling force exerted through a rope
• What is the normal contact force also known as?

  The reaction force
• How does the normal contact force act on a rock on a table?

  It acts upwards against the rock's weight
• What are the three types of non-contact forces mentioned?

  Gravitational, magnetic, and electrostatic forces
• What is gravitational force?

  A force of attraction between masses
• How do magnetic forces behave?

  They can be attractive or repulsive
• What can electrostatic forces do?

  Be attractive or repulsive between charges
• How does the strength of non-contact forces change with distance?

  It decreases as objects get further apart
• What are the characteristics of contact forces?

  • Require physical touching
  • Examples include friction and tension
  • Act directly between objects
• What are the characteristics of non-contact forces?

  • Do not require physical touching
  • Examples include gravitational, magnetic, and electrostatic forces
  • Act through fields of influence
• Compare contact forces and non-contact forces.

  • Contact forces: require touch, e.g., friction
  • Non-contact forces: act at a distance, e.g., gravity