Oscillation is the repetitive back-and-forth motion of an object around a central point or equilibrium position. Think of a pendulum swinging, a spring bouncing, or a guitar string vibrating – these are all examples of oscillations.

Here’s a breakdown of the key concepts:

1. Equilibrium Position

  • The central point: This is the position where the object would rest if it were not disturbed.
  • Restoring force: When the object is displaced from its equilibrium position, a force acts to pull it back towards the center.

2. Types of Oscillations

  • Periodic Oscillation: The motion repeats itself in a regular cycle, with a fixed time period.
  • Non-periodic Oscillation: The motion doesn’t repeat in a regular pattern.
  • Damped Oscillation: The amplitude (maximum displacement) of the oscillation decreases over time due to energy loss (e.g., friction).
  • Forced Oscillation: An external force drives the oscillation (e.g., pushing a swing).
  • Resonance: Occurs when the frequency of the external force matches the natural frequency of the system, leading to a large increase in amplitude. 

3. Key Terms

  • Displacement: The distance of the object from its equilibrium position at any given time.
  • Amplitude: The maximum displacement from the equilibrium position.
  • Period (T): The time taken for one complete oscillation.
  • Frequency (f): The number of oscillations per unit time. f = 1/T
  • Angular Frequency (ω): ω = 2πf = 2π/T

4. Simple Harmonic Motion (SHM)

  • A special type of oscillation: The restoring force is directly proportional to the displacement and acts in the opposite direction.
  • Equation: F = -kx (where k is the spring constant)
  • Examples: Mass-spring system, simple pendulum (for small angles).

5. Applications of Oscillations

Oscillations are everywhere in physics and engineering:

  • Mechanical systems: Springs, pendulums, vibrations in structures.
  • Electrical circuits: LC circuits, AC current.
  • Waves: Sound waves, light waves, water waves.
  • Quantum mechanics: Vibrations of atoms and molecules.

Formula Sheet