• Force: It is a push or pull that one object exerts on another which produces, or tends to produce motion, stops or tends to stop motion.

    • Unit: N

    • Examples of forces are:

      weight; tension; magnetic force; electric force; contact force; friction; resistance;

  • Addition of vectors

    • Simply add / subtract if vectors are acting in a line.

    • Law of Parallelogram:

    • Head-to-tail Rule:

  • Newton’s Laws of Motion

    • First Law: Every object continues in its state of rest or uniform motion in a straight line unless a resultant force acts on it to change its state.

    • Second Law: Acceleration of a mass is directly proportional to the resultant force.

      F ∝ a

      F = m a

      Note: Acceleration has the same direction as the resultant force.

    • Third Law: To every action there is an equal and opposite reaction.

  • Balanced forces

    • When there is no resultant force

      • acceleration will be zero (2nd Law)

      • no change in state of motion (1st Law)

  • Unbalanced forces

    • When there is a resultant force

      • acceleration will NOT be zero (2nd Law)

      • change in state of motion(1st Law)

  • Friction: It is the force that opposes motion.

    • It has advantages and disadvantages.

    • Friction is affected by

      • lubrication / oiling

      • how hard the surfaces are rubbed together

      • nature of the surfaces in contact

    • Types

      • Static friction is the friction when a body is not moving.

      • Limiting friction is the (maximum static) friction when a body is just about to move.

      • Dynamic friction is the friction when a body is moving.

      Note: Dynamic friction is always less than limiting friction.

If you are interested in any of our services, then find out ways of contacting us.

Have questions? See our compilation of questions and answers.