Chapter 2 — Chapter 2 — Simple Harmonic Motion

Oscillatory motion is a to and fro motion about a mean position; it is a periodic motion which repeats itself after an equal interval of time. Examples: simple pendulum, mass on a spring, tuning fork, atoms in solids, swing, air molecules carrying sound, guitar strings, wings of birds. When a body is displaced from its mean position, a restoring force brings it back. Vibration: one complete round trip (cycle) about the mean position. Instantaneous displacement x: distance from the mean position at any instant. Amplitude x₀: magnitude of the maximum displacement on either side. Time period T: time to complete one vibration (s). Frequency f: number of vibrations per second, f = 1/T (Hz). Angular frequency ω = θ/t = 2π/T = 2πf (rad s⁻¹).