Units 1 and 2 Review

Question 1

Wave

Answer 1

A repeating disturbance that transfers energy from one place to another.

Question 2

Pulse

Answer 2

As a wave travels, energy is transferred. A pulse is formed when the energy is transferred one time only.

Question 3

Transverse

Answer 3

Particles vibrate perpendicularly (up and down) to the direction the wave travels.

Question 4

Longitudinal

Answer 4

­Particles vibrate parallel to the direction the wave travels.

Question 5

Compression

Answer 5

An area where the coils are close together.

Question 6

Rarefaction

Answer 6

­An area of a wave where the coils are spread out.

Question 7

Crest

Answer 7

The highest point of the wave.

Question 8

Trough

Answer 8

The lowest point of a wave.

Question 9

Surface Wave

Answer 9

­A combination of longitudinal waves and transverse waves. A ripple on a pond is an example of this combined wave type.

Question 10

Blast Wave

Answer 10

­A high-­pressure wave that radiates out with great energy from the center of an explosion.

Question 11

Amplitude

Answer 11

­A measure of how far a particle in the medium moves away from its normal rest position. Amplitude is half of the difference between the crest and the trough.

Question 12

Wavelength

Answer 12

­The distance from any point on a wave to an identical point on the next wave pulse. Wavelength measures the length of one cycle, or repetition, of a wave.

Question 13

Frequency

Answer 13

­The number of waves produced in a set amount of time.

Question 14

Hertz

Answer 14

The unit of measure that FREQUENCY is usually expressed in. (Hz).

Question 15

Wave Speed

Answer 15

­The rate at which a wave travels.
*It can be calculated by multiplying wavelength and frequency.
v = λ x f
λ = lambda (greek)
wave speed = wavelength x frequency

Question 16

Medium

Answer 16

­A material through which the energy of the wave
moves from one place to another. The medium can
be air, water, steel, or any other material.

Question 17

Mechanical Wave

Answer 17

A wave that travels through a medium due to the
motion of matter. Sound is an example.

Question 18

Sound Wave

Answer 18

A mechanical wave caused by the vibration of
particles as the waves travel through a medium. Can travel through solids, liquids, or gasses. Travels
fastest through solids.

Question 19

Absorption

Answer 19

Absorption refers to a medium converting the
energy of a mechanical wave into other forms. When energy is absorbed by a medium, the medium gains thermal energy and the wave loses that energy.

Question 20

Reflection

Answer 20

When a wave encounters a boundary in the
medium, reverses direction, and travels back through the original medium.

Question 21

Transmission

Answer 21

When a mechanical wave encounters a new
medium and moves into the new medium.

Question 22

Light

Answer 22

A type of energy that travels as waves. Light is different from other kinds of waves. Other kinds of waves, like sound waves and water waves, must travel through matter. Light does not require matter through which to travel. Light is an
electromagnetic wave.

Question 23

Electromagnetic Wave

Answer 23

­As the word electromagnetic (EM) suggests, these waves have two parts. They are made up of changing electric and magnetic fields. When an electrically charged particle vibrates, it disturbs the electric and magnetic fields around it. These two
vibrating fields produce EM waves. EM waves do not need a medium in which to travel.

Question 24

Visible Light

Answer 24

Light that we readily see is called visible light. It is essential for human vision.

Question 25

Ultraviolet Light

Answer 25

A type of light that cannot be seen by humans (bees see it).

Question 26

Electromagnetic Spectrum

Answer 26

The EM spectrum is composed of many different types of EM waves, including x­rays, radio waves, and microwaves.

Question 27

ROY G BIV

Answer 27

An acronym used to remember the colors of the visible light spectrum. (red, orange, yellow, green, blue, indigo, violet)

Question 28

Lumens

Answer 28

The unit of measure brightness is measured in. For light waves, the greater the amplitude, the brighter the light.

Question 29

Filter

Answer 29

A medium that transmits certain wavelengths but absorbs others. For example, a red filter would transmit the wavelength corresponding to the red color but block other visible light wavelengths.

Question 30

Color Addition

Answer 30

Combining colors of light.

Question 31

Primary Colors of Light

Answer 31

Red, blue, and green.

Question 32

Secondary Colors of Light

Answer 32

Cyan, magenta, and yellow. This is the result of mixing two primary colors together.

Question 33

Transmission (In Terms of Light)

Answer 33

The passing of light waves through matter. The medium through which light passes can transmit all, some, or none of the light.

Question 34

Transparent

Answer 34

Light fully and straightly transmits through these materials and objects can be seen clearly through them.

Question 35

Translucent

Answer 35

Transmits light but not straight through, the light is scattered into many different directions. An object appears distorted or fuzzy through a translucent material.

Question 36

Opaque

Answer 36

Materials do not allow any light to transmit through. Instead, they reflect light, absorb light, or both.

Question 37

Absorption (In Terms of Light)

Answer 37

The transfer of light energy to matter. When light enters a material but does not leave it, the light is absorbed.

Question 38

Reflection

Answer 38

The bouncing of light off of a surface, such as a mirror.

Question 39

Kaleidoscope`

Answer 39

A toy that uses mirrors and little pieces of colored glass, bits of colored paper, or other small objects used to produce beautiful, ever-changing patterns.

Question 40

Refraction

Answer 40

The bending, or change in direction of a light wave as it passes from one medium to another. This bending of a light wave is due to the change in speed of the wave as it enters a new medium.

Question 41

Communication

Answer 41

Sharing information through speaking, gestures, or sign language to share ideas and experiences. Both encoding and decoding are necessary for this.

Question 42

Signal

Answer 42

Anything that transmits information.

Question 43

Encoding

Answer 43

To convert information from one form to another for the purpose of communication.

Question 44

Decoding

Answer 44

To interpret or decode a message. Or to find out what a signal means.

Question 45

Morse Code

Answer 45

An international code that uses combinations of 2 pulses of different lengths to represent numbers and letters. A dash is used to represent a long pulse, and a dot is used for a short pulse.

Question 46

Modulation

Answer 46

The process of varying the property of a wave in order to encode information into the wave. Usually, the amplitude or the frequency of the wave is varied so that complex information can be communicated.

Question 47

Frequency Modulation

Answer 47

A wave that has been modulated based on its frequency. It varies from one wavelength to the next.

Question 48

Amplitude Modulation

Answer 48

A wave that has been modulated based on its amplitude.

Question 49

Digital Signal

Answer 49

A signal that contains digital information. Digital information is not continuous and instead only contains a number of distinct values. An example could be the presence or lack of a signal fire. When the fire is present, people know that help is needed. When the fire is not present, everyone is safe.

Question 50

Analog Signal

Answer 50

A signal that contains analog information. Analog information is continuous and can be any value. A graph will show smooth changes between values. An example could be a light signal, a sound signal, or an electromagnetic wave signal if analog information were encoded into them.

Question 51

Binary Digital Signal

Answer 51

A digital signal that has only 2 values; "on" or "off" which are represented as the numbers 1 & 0.

Question 52

Carrier Wave

Answer 52

A wave that can be modulated in order to add digital information to the signal.

Question 53

Noise

Answer 53

Any unwanted change to a signal (does NOT only apply to sound). Noise can affect all types of signals. Sunlight can make it hard to see a fire. Electronics can interfere with electric signals. Noise can occur any time a signal is transmitted, stored, or recorded. Whenever the signal that reaches the intended receiver is different from the signal that was originally transmitted, noise has affected the signal.