Chapter 11 (black ink) lecture notes (blue ink) textbook notes. Simple harmonic motion (sinusoidal motion): periodic motion which is described by a sine function. The motion that results when the force on a mass is exactly proportional to the displacement of the mass from its rest position. Elongation: (x) (units in m) stretching (like of a string) Weight: how much the mass gets pulled down by gravity. Acceleration of gravity: (g) (m/s^2) how much additional speed the mass picks up every second (earth: 9. 8m/s^2) Frequency does not depend on amplitude- at least in simple harmonic motion. Our ears detect simple harmonic motion as 1 frequency. A scale is just the gravity force on our body. A plot of position versus time is a sine wave. Increasing the spring constant increases the oscillation frequency. The oscillation frequency of a simple harmonic oscillator does not depend on the amplitude of the oscillation.