Understanding Waves: Properties and Types

• STUDY NOTES DAY 1

Waves

• A wave is a disturbance that travels through something.
• Amplitude is the size/height of the wave.
• Wavelength is the distance from one wave to another.
• Mechanical waves transmit through a medium (matter).
  • Transverse waves vibrate particles perpendicularly to the direction of travel.
  • Longitudinal waves vibrate particles in the same direction.
• Electromagnetic waves can travel through a vacuum (empty space).
  • Compression occurs when particles of a medium are close together.
  • Rarefaction occurs when particles spread further apart.

Characteristics of a Wave

• Wavelength is the distance between two points on a wave.
• Frequency is the number of wavelengths passing a point per unit of time.
  • Audible frequencies range from 20Hz to 20000Hz.
  • Ultrasonic frequencies are above 20000Hz.
  • Infrasonic frequencies are below 20Hz.
• Amplitude is the distance between the trough and equilibrium position.
• Wave speed is how fast a wave moves, measured in m/s or km/hr (v = λf).
  • λ represents wavelength.
  • f represents frequency (Hz).
• Sound waves are longitudinal waves produced by vibrations.
  • Intensity is the quality of sound directly affected by frequency.
  • Pitch is the highness or lowness of a sound.
  • Loudness is the human perception of sound volume.
• The Doppler Effect is the observed change in a wave's frequency due to relative motion between source and observer.
• Electromagnetic (EM) radiation is a special kind of energy that travels in waves through space.

Electromagnetic Radiation

• Radio Waves: allow for listening to the radio.
• Microwaves: shorter wavelengths and higher frequencies than radio waves.
• Infrared Radiation: has longer wavelengths than visible light, and is sometimes called heat radiation.
• Visible Light: allows us to see and comes in different colors.
• Ultraviolet Radiation: shorter wavelengths and higher frequencies than visible light, and comes from the sun.
• X-Radiation: shorter wavelengths and higher frequencies than UV radiation, used to see bones and organs.
• Gamma Radiation: shortest wavelengths and highest frequencies, are produced during nuclear reactions.

Light

• Light is a form of energy that helps you see things and moves in a straight line called a ray.
• Visible light allows us to see the world around us.
• Color: perceived based on different wavelengths of light.
  • Opaque materials absorb or reflect all wavelengths.
  • Transparent/lucent materials transmit nearly all light.
  • Primary colors of light are red, green, and blue (RGB).
  • Green + blue = cyan, blue + red = magenta, red + green = yellow.
  • Combining all primary colors of light reflects white.
• Cones detect different colors and send signals to our brain.
• Rods become active in the dark.

Modes of Heat Transfer

• Conduction is the transfer of heat between substances in direct contact.
  • Conductors easily move heat.
  • Insulators do not easily allow heat transfer.
• Convection occurs when liquids & gases rise when heated and sink when cooled.
• Radiation does not rely on contact between the heat source & object.

Text Structure

• How a piece of writing is organized.
• Expository Text explains about a topic.
  • Cause & Effect explains why something happens and what happens because of it.
  • Compare & Contrast shows how 2 things are alike and different.
  • Description describes a topic by explaining its characteristics.
  • Problem & Solution explains a problem, then gives a solution.
  • Sequence explains events in a chronological order.
• Journalistic Text tells true information about events, shares facts, and helps people make good decisions.
• Inverted Pyramid summarizes information to get the reader's attention.

Linguistic

• Linguistic = language
• Linguistic Feature = special parts of language that makes it easier to understand.
• How words & sentences work
  • Lexical = more focused on the words that we use
    • Synonyms = Words with same meanings
    • Antonyms = Words with different meanings
    • Homonyms = same spelling/sound, different meaning.
    • Word Choice = choosing the right words
  • Syntactic = how we arrange words to make it understandable
    • Word Order
    • Types of Sentences

Sentence Structure

• Simple Sentence = a sentence with an independent clause (complete thought)
  • Subject + Verb
• Compound Sentence = a sentence with 2 complete thoughts joined by a coordinating conjunction
  • IC + Coordinating Conjunction + IC
  • Coordinating Conjunctions – FANBOYS (For, and, nor, but, or, yet, so)
• Complex Sentence = a sentence with an independent clause and dependent clause (cannot stand alone)
  • IC + Subordinating Conjunction + DC
  • Subordinating Conjunction – connects DC w/ IC, showing cause, time, conflict, and condition.

Writing

• Cohesion & Organization = writing which is clear and easy to understand.
  • Cohesion = all parts of a text are connected
  • Organization = ideas are arranged in the right order
• Rhetorical = special ways to use words
  • Asking Questions = makes the reader think, but doesn't need an answer.
  • Comparing things w/ Similes & Metaphors

Information

• Informational Text provides information about real-world issues.
  • Facts = words proven true
  • Opinions = statements from personal beliefs

Finding Info

• STEPS HOW TO FIND INFORMATION
  • Identify key statements that have data.
  • Check for sources w/ supportable facts.
  • Distinguish Fact vs. Opinion.
  • Look for Bias.

Visual

• Visual = something that you can see.
  • Ex: Maps, charts, diagrams.

Visual Elements

• Graphic features that help readers understand.
  • Graphs & Charts = used for numerical data.
  • Diagrams = shows the structure of something.
    • Labeled diagram, flow chart, lifecycle diagram, timeline.
    • Maps.
  • Maps = used to show geographical locations.
    • Elements of Arts.
  • Photographs give a realistic/artistic representation about a topic.
  • Tables organizes data into rows & columns.