WAVES Chapter 13: Harmonic Motion, Sound, & Light Waves

Vocabulary practice flashcards covering harmonic motion, sound, light waves, ray diagrams, and signal types from Chapter 13.

Linear motion

Motion that proceeds along a straight path in a single direction without repeating or oscillating.

Harmonic motion

Motion that repeats itself over and over in regular cycles; also known as periodic motion.

Oscillator

A physical system that undergoes repeating, back-and-forth periodic or harmonic motion around an equilibrium position.

Pendulum

An oscillating system consisting of a suspended weight that swings back and forth whose period can be influenced by length, mass, and release angle.

Cycle

One complete unit of repeating harmonic motion that returns an oscillator to its original starting state.

Period

The amount of time required to complete one full cycle of harmonic motion.

Frequency

The number of complete cycles or oscillations completed per unit of time, calculated using the period-frequency formula.

Hertz

The standard SI unit of frequency, representing one cycle per second.

Amplitude

The maximum displacement or distance of an oscillator from its center equilibrium position.

Damping

The gradual decrease in amplitude and energy of an oscillating system over time due to friction or resistance.

Stable systems

Systems that naturally develop restoring forces to return to their equilibrium point after being disturbed.

Unstable systems

Systems in which a disturbance produces forces that drive the system farther away from equilibrium rather than restoring it.

Restoring force

A force that consistently acts to push or pull an oscillating object back toward its equilibrium point.

Inertia

The tendency of an object to resist changes in its state of motion (Newton's 1st Law), causing a moving oscillator like a pendulum to swing past equilibrium.

Phase

The relationship describing the relative timing and alignment between two oscillating waves or systems (e.g., in-phase or out-of-phase).

Natural frequency

The specific frequency at which an oscillating system naturally vibrates or cycles when disturbed.

Analog signal

A continuous signal that conveys information through continuous variations in wave properties.

Digital signal

A discontinuous signal that transmits information encoded as discrete values or binary sequences.

Refraction

The bending of a wave or light ray as it crosses the boundary from one medium into another medium of differing wave speed.

Index of refraction

A value that describes how much light slows down and bends when crossing into a new medium.

Reflection ray diagram

A diagram illustrating the Law of Reflection, displaying an incident ray reflecting off a mirror surface such that the angle of incidence equals the angle of reflection relative to the normal line.

Refraction ray diagram

A diagram depicting a light ray traveling across a boundary from air into water, bending toward the normal line with angle of incidence $\theta_1$ and angle of refraction $\theta_2$.

Harmonic motion graph

A position versus time plot for an oscillating pendulum bob, showing an amplitude of $20\,\text{cm}$ and a period of $1.5\,\text{sec}$ per full cycle.