A20 TEST: Mechanical Waves (FINAL)

Mecanical 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. (CREST OR TROUGH)

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

(COMPRESSION OR RAREFICATION)

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

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

Amplitude

Displacement from the line of equilibrium to the height of a crest or trough.

Crest

The highest displacement from the line of equilibrium.

Trough

The lowest displacement from the line of equilibrium.

Frequency (𝑓) unit (Hz)

The number of waves that pass a given point in a second of time.

Wavelength (λ) unit( m or cm)

Shortest distance between points of a wave, where the wave pattern repeats itself. You count them from crest to crest or from trough to trough

Wavespeed

Speed at which a wave travels throught a medium. It depends solely on the properties of the medium. Inderpendent of the wavelength or the frequency.

Pulse

a thing in a wave which is like a single burst of energy - a one-time disturbance that travels through a medium

Nodes

are the result of the meeting of a crest with a trough; this form of-

Interference is known as destructive interference and leads to a point-

of (NO DISPLACEMENT). In short, a point where there is no displacement.

Antinodes

are positions along the medium that undergo maximum

displacement from a high upward displacement to a high downward

displacement. They are the result of a crest meeting a crest to

form a supercrest and a trough meeting a trough to form a supertrough

Law/Principle of Superposition (Constructive, Complete and Incomplete Destructive)

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

Contructive Interference

When waves add up.

1. Two waves come together and their high points (crests) match up.

2. The waves combine to make a bigger wave.

3. The result is taller wave

Complete Destructive Interference

When waves cancel out.

1. Two waves meet, but one is up (crest) and the other is down (trough).

2. They cancel each other out

3. the result is an oppsite wave

Incomplete Destructive Interference

When waves kind of cancel.

1. Two waves meet

2. They partly cancel out, but not completely.

3. The result is a smaller wave

Interference

the result of superposition

Diffraction

is the bending of waves around the barrier.

Refraction

is the bending of light (or any wave) as it passes from one medium into another, causing it to change direction. Happens due to change in medium.

Laws of Refraction

Frequency remains constant

Wavelengths and wave velocity might change

Waves also might change direction

Normal

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

What determins the speed of a wave?

Properties of the medium

Type of wave (mechanical wave or electromagnetic wave)

mechanical

_____ waves require a material medium for energy transfer.

transverse

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 ____

period

the time needed for an object to complete one full cycle of simple hamonic motion is the ______

inteference

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

node

when waves are superposed, any point that does not experience any displacement is ______

wave

A disturbance that carries energy through matter or space in an ____

amplitude

The maximum distance an object in a simple harmonic motion moves from its equilibrium is called the ______

trough

the lowest point of a transverse wave is a _____

wavelength

The shortest distance between two points where the wave patterns repeats itself is a _____

antinode

When two waves interfere constructively, the point with the greatest displacement is called the _____

frequency

The number of complete oscillations a wave makes each secound is the ______ of the wave

refraction

_____ refers to the change in direction waves experience at the boundary between two diffrent media.

how do you find distance?

d = vt

more dense → less dense medium

Reflected wave: erect
Transmitted pulse: erect

less dense → more dense medium

Reflected wave: inverted
Transmitted pulse: erect

greatest

The wave speed and wavelength are always ____ in the less dense medium

frequency

The ____ of a wave is not altered by crossing a boundary.