Chapter 1: The Nature of Sound Waves

Vocabulary flashcards covering key concepts from Chapter 1: The Nature of Sound Waves.

Sound

Changes in pressure produced by a vibrating object, propagated through a medium (e.g., air or water), and detectable by the ears.

Acoustics

Branch of physics that studies sound—from its physical properties to its production, transmission, and effects.

Matter

Anything that has mass and takes up space.

Energy

The capacity to do work; energy is transferred rather than destroyed.

Mass

The amount of matter present; a measure of inertia; applies to gases, liquids, and solids.

Elasticity

Property that enables recovery from distortion of shape or volume.

Transmitting medium

Medium through which sound travels (e.g., air, water, steel); without a medium, sound cannot occur.

Inertia

Resistance to changes in motion; directly related to mass.

Newton's First Law (Inertia)

Objects remain at rest or in uniform motion unless acted on by an external force.

Newton's Third Law

For every action, there is an equal and opposite reaction.

Vibration

Back-and-forth movement of a source that produces sound.

Wave

Propagation of energy through a medium as density fluctuations (e.g., compressions and rarefactions).

Compression

Region of increased density in a medium within a wave.

Rarefaction

Region of decreased density in a medium within a wave.

Displacement

Change in position; a vector quantity with magnitude and direction.

Velocity

Rate of change of displacement; a vector quantity, often denoted as c; equals Δx/Δt.

Speed

Scalar quantity; magnitude only; distance traveled per unit time.

Acceleration

Rate of change of velocity; a vector quantity; can be positive (acceleration) or negative (deceleration).

Density

Mass per unit volume (ρ = m/v); density can change with height above sea level.

Mass vs Weight

Mass is the amount of matter present; weight is the gravitational force acting on that mass.

State of Matter

The physical form of matter—solid, liquid, or gas—based on molecular arrangement.

Solid

Maintains shape and volume; particles are closely packed and can only vibrate.

Liquid

Maintains volume but takes the shape of its container; molecules slide past one another.

Gas

Expands to fill the container; has neither fixed shape nor fixed volume.

Fundamental physical quantities

Length, Mass, and Time; all other quantities are derived.

Length

A measure of distance; SI unit is the meter (m).

Time

A quantity measured in seconds (s); fundamental unit for temporal measurement.

Mass (units)

SI unit is kilogram (kg); base unit for mass.

Derived quantities

Quantities obtained from fundamental quantities, such as displacement (x), velocity (v or c), acceleration (a), force (F), and pressure (p).

Displacement (x)

Change in position; a vector quantity with magnitude and direction.

Force

A push or pull that can cause or resist motion; central to Newton's laws.

Pressure

Force per unit area; a derived physical quantity related to the interaction of forces within a medium.

System of Units

Framework for measuring units; includes Metric (MKS/CGS) and English (fps) systems.

Metric System (SI)

International System of Units used worldwide in science.

MKS, CGS, FPS

Different systems of units: MKS (meter-kilogram-second), CGS (centimeter-gram-second), FPS (foot-pound-second).

Air as a medium (molecules per volume)

Air contains approximately 400 billion billion (4×10^20) molecules per cubic inch, illustrating a dense transmitting medium.