chapter 19-20

This set of flashcards covers the key concepts of vibrations, waves, sound, and relevant phenomena as outlined in the lecture notes.

Vibration

A periodic wiggle in time.

Wave

A periodic wiggle in both space and time that extends from one place to another.

Pendulum's Period

Depends only on the length of the pendulum and does not depend upon the mass.

Crest

The high point of a wave.

Trough

The low point of a wave.

Amplitude

Distance from the midpoint to the crest or to the trough.

Wavelength

Distance from the top of one crest to the top of the next crest.

Frequency

Specifies the number of vibrations in a given time, measured in Hertz (Hz).

Period

The time to complete one vibration.

Wave Speed

Describes how fast a disturbance moves through a medium; related to frequency and wavelength.

Transverse Wave

Medium vibrates perpendicularly to the direction of energy transfer.

Longitudinal Wave

Medium vibrates parallel to the direction of energy transfer, consisting of compressions and rarefactions.

Wave Interference

Occurs when two or more waves interact because they occur in the same place at the same time.

Constructive Interference

When waves reinforce each other.

Destructive Interference

When waves cancel each other out.

Standing Waves

Waves that remain in a constant position, with nodes and antinodes.

Nodes

Regions of minimal or zero displacement in a standing wave.

Antinodes

Regions of maximum displacement in a standing wave.

Doppler Effect

Increase in frequency when the source approaches you (blue shift) and decrease when it moves away (red shift).

Sonic Boom

A shock wave produced when an object travels faster than the speed of sound.

Infrasonic Waves

Sound waves with frequencies below 20 Hz (too low for human hearing).

Ultrasonic Waves

Sound waves with frequencies above 20,000 Hz (too high for human hearing).

Acoustics

The study of sound.

Refraction of Sound

Bending of waves caused by changes in speed affected by wind variations and temperature.

Resonance

A phenomenon where forced vibrations match an object's natural frequency.

Beats

Periodic variations in loudness due to interference of waves.

Natural Frequency

An object's unique frequency dependent on its elasticity and shape.

Reflection (echo)

The process in which sound encounters a surface and is returned.