Published on: January 31, 2024

TYPES OF FORCES

TYPES OF FORCES

Forces are fundamental to the understanding of motion and interactions in the physical world. They can be broadly classified into two categories: contact forces and action-at-a-distance forces.

CONTACT FORCES:

  1. NORMAL FORCE:
    • Definition: The normal force is a contact force exerted by a surface to support the weight of an object resting on it.
    • Direction: Always perpendicular to the surface.
    • Example: When you place a book on a table, the table exerts a normal force upward, counteracting the force of gravity pulling the book downward.
  2. FRICTIONAL FORCE:
    • Definition: Friction is a force that opposes the relative motion or tendency of such motion of two surfaces in contact.
    • Types:
      • STATIC FRICTION: Acts on objects at rest.
      • KINETIC FRICTION: Acts on objects in motion.
    • Example: The friction between the tires of a car and the road surface provides traction for the vehicle.
  3. TENSION FORCE:
    • Definition: Tension is the force transmitted through a string, rope, cable, or any other flexible connector.
    • Example: In a simple pendulum, the tension in the string keeps the mass in circular motion.
  4. APPLIED FORCE:
    • Definition: Applied force is a force exerted on an object by a person or another object.
    • Example: Pushing a car requires applying force to overcome inertia and move the car.

ACTION-AT-A-DISTANCE FORCES:

  1. GRAVITY:
    • Definition: Gravity is the force of attraction between two masses.
    • Strength: Proportional to the masses and inversely proportional to the square of the distance between them.
    • Example: Earth’s gravity pulls objects towards its center, giving weight to everything on its surface.
  2. ELECTROMAGNETIC FORCE:
    • Definition: Electromagnetic forces arise between charged particles.
    • Types:
      • ELECTROSTATIC FORCE: Between stationary charges.
      • MAGNETIC FORCE: Between moving charges or magnets.
    • Example: Magnets attracting or repelling each other.
  3. NUCLEAR FORCES:
    • Definition: Forces acting within atomic nuclei to hold protons and neutrons together.
    • Strong Nuclear Force: Attractive force binding protons and neutrons.
    • Weak Nuclear Force: Responsible for certain types of radioactive decay.
    • Example: Maintaining the stability of atomic nuclei.
  4. SPRING FORCE:
    • Definition: Force exerted by a compressed or stretched spring.
    • Hooke’s Law: The force is directly proportional to the displacement from the equilibrium position.
    • Example: Compressing a spring in a ballpoint pen to release ink.

  5. BUOYANT FORCE:

    • Definition: Buoyant force is exerted by a fluid (liquid or gas) on an object immersed in it, counteracting the force of gravity.
    • Example: A boat floating on water experiences an upward buoyant force equal to the weight of the water it displaces.