Mechanical Waves: Types and Properties

Waves

A vibration or oscillation that transfers energy.

Mechanical Waves

Wave motion that requires a medium (ie, water, sound, slinkie).

Transverse Waves

The vibration of the individual particles of the medium is perpendicular to the direction of wave propagation; the Medium is displaced perpendicular to the direction of the wave.

Longitudinal Waves

The vibration of the individual particles is parallel to the direction of wave propagation; the medium is displaced parallel to the direction of the wave.

Surface Waves

The medium is displaced perpendicular and parallel to the direction of the wave.

Electromagnetic Waves

No medium is needed (light, radio waves, X-rays).

Standing Wave

when two identical waves (same frequency, wavelength, and amplitude) travel in opposite directions and interfere with each other in the same medium.

Pulse

A pulse in the wave is like a single burst of energy - a one-time disturbance that travels through a medium.

Wavelength

The shortest distance between points of a wave - where the wave patterns repeat themselves.

Node

A point of no displacement resulting from the meeting of a crest with a trough; this form of interference is known as destructive interference.

Antinode

Positions along the medium that undergo maximum displacement from a high upward displacement to a high downward displacement.

Law/Principle of Superposition

When two or more waves exist in the same medium, each wave moves as though the other were absent.

Interference

The result of superposition.

Diffraction

The bending of waves around a barrier; the effects of diffraction get less obvious as the gap gets larger.

Refraction

The bending of light (or any wave) as it passes from one medium into another, causing it to change direction.

Normal

An imaginary line that is perpendicular to the surface at the point where a wave (like light) hits that surface/boundary.

Speed of a Wave

Determined by properties of the medium and the type of wave (mechanical wave or electromagnetic wave).

Frequency

Does not change from one medium to another.

Energy

Does not change from one medium to another.

Wavelength (Change)

Changes when passing from one medium to another.

Amplitude

In incomplete interference, amplitudes change meaning they don't fully increase or decrease.

Crest

The highest point of a wave.

Trough

The lowest point of a wave.

Supercrest

A result of a crest meeting a crest.

Supertrough

A result of a trough meeting a trough.

mechanical

_____ waves require a material medium for energy transfer

transversal

A(n) _____ wave causes the particles of the medium to vibrate in a direction perpendicular to the direction in which the wave travelling

electromagnetic

______ waves need no medium for travel

pulse

A(n) _____ is a single disturbance traveling through a medium

frequency

The _______ of a wave is the number of waves that pass a given point per second

period

The ______ of a wave is the reciprocal of its frequency, as well as The time needed for an object to complete one full cycle of simple harmonic motion

wavelength

The _______ of a wave is the linear distance between any two corresponding points on consecutive waves

amplitude

The energy content of a mechanical wave is characterized by _____

interference

_____ occurs when more than one wave moves through the same medium at the same time

speed

The ________ of a mechanical wave depends on the medium

frequency

When waves pass from one medium into another, their _____ remains unchanged

standing

A(n) _____ wave is produced when a wave train moving direction meets an identical wave train moving in the opposite direction

node

Two pulses with identical shapes but opposite displacements move toward each other in a medium. The point in the medium that is not displaced is a(n) _____

refraction

_______ is the direction change of waves at the boundary between different medie

diffraction

______ is the bending of a wave around an obstacle

normal

The _______ is a line perpendicular to a barrier at the point where an incident ray strikes the barrier

incidence

When a wave is reflected from a barrier, the angle of _____ equals the angle of reflection

energy

Waves provide a means of transferring ______

small

If the amplitude of the reflected pulse is ______ when a wave passes from one medium to another, most of the energy has been transmitted

frequency

When waves refract, the waves do not change ____

medium

A mechanical wave is different from other types of waves because it requires a(n) ____

longitudinal

Sound waves are ____ waves

both transverse and longitudinal waves

A surface wave is a wave that has characteristics of ____