Glossary
Continuous Waves
Periodic disturbances that repeat over time and space, characterized by consistent wavelengths and frequencies.
Example:
The steady hum from a tuning fork produces continuous waves of sound that propagate through the air, maintaining a constant pitch.
Electromagnetic Waves
Waves that consist of oscillating electric and magnetic fields, capable of traveling through a vacuum and not requiring a material medium.
Example:
Sunlight reaching Earth is composed of electromagnetic waves that traverse the vacuum of space, carrying energy from the sun.
Energy Transfer
The process by which energy moves from one location to another, often through a medium, without the physical displacement of the medium's matter.
Example:
When you speak, your vocal cords create sound waves that cause the air molecules to vibrate, transferring sound energy transfer to a listener's ear without the air itself moving from your mouth to their ear.
Longitudinal Waves
Waves in which the oscillations of the medium are parallel to the direction of wave propagation.
Example:
When a Slinky is pushed and pulled along its length, it creates a longitudinal wave with compressions and rarefactions moving in the same direction as the disturbance.
Mass per unit length (m/ℓ)
A measure of how much mass is contained in a given length of a string or wire, inversely influencing the speed of waves on it.
Example:
A thicker, heavier rope has a larger mass per unit length than a thin string, causing waves to travel slower on the rope for the same applied tension.
Mechanical Waves
Waves that require a physical medium (solid, liquid, or gas) to propagate and transfer energy.
Example:
The ripples created when a stone is dropped into a pond are mechanical waves because they need water to travel and cannot exist in a vacuum.
Speed of Light (c)
The constant speed at which all electromagnetic waves travel in a vacuum, approximately $3.00 imes 10^8 ext{ m/s}$.
Example:
Radio signals from a distant satellite travel to Earth at the speed of light, allowing for near-instantaneous communication across vast distances.
Tension (F_T)
The pulling force transmitted axially through a string, cable, or similar continuous object, which directly affects the speed of waves on that object.
Example:
Increasing the tension on a guitar string makes the pitch higher because it increases the speed of the waves traveling along the string, leading to a higher frequency.
Transverse Waves
Waves in which the oscillations of the medium are perpendicular to the direction of wave propagation.
Example:
Shaking a jump rope up and down creates a transverse wave where the rope moves vertically while the wave travels horizontally along its length.
Wave Amplitude
The maximum displacement or distance moved by a point on a vibrating body or wave measured from its equilibrium position.
Example:
Turning up the volume on a speaker increases the wave amplitude of the sound waves, making the sound perceptibly louder.
Wave Pulse
A single, non-repeating disturbance that propagates through a medium, carrying energy from its source.
Example:
Snapping a whip creates a single, sharp wave pulse that travels down its length, demonstrating a one-time energy transmission.
Wave Speed
The rate at which a wave propagates through a medium or space, determined by the properties of the medium.
Example:
The wave speed of sound is much faster in water than in air due to water's higher density and stiffness, allowing sound to travel more quickly.