BELLWORK 3/25/13 Check Extra Credit of the Week! Answer your Bellwork in your composition book in the inside margin of pg.143. What do you think of when you hear the word wave? Write a brief description in your composition book of what you think a wave is. Then write at least 2 sentences describing a time you might have experienced waves.
WAVES: is a disturbance that is a transfer of energy through space or a medium.
Wave A wave is a DISTURBANCE that travels through a medium from one location to another What in the world is a “medium?” Medium is MATTER The wave travels through some sort of matter
The “Medium” of a Wave… A medium is the substance or material the wave travels through Can be a SOLID, LIQUID, or GAS Example: Seismic waves (earthquakes) travel through the ground Ocean waves travel through water
Longitudinal vs. Transverse Waves
Examples: light waves, water waves electromagnetic waves, and spring A. Transverse Waves Examples: light waves, water waves electromagnetic waves, and spring
Parts of Transverse Waves Crest - above the line Trough - below the line
Transverse Particle Motion Particles or energy moves perpendicular to wave motion
Water Waves
Check for Understanding… 1. A transverse wave is transporting energy from east to west. The particles of the medium will move_____. a. east to west only b. both eastward and westward c. north to south only d. both northward and southward
B. Longitudinal Waves Examples: sound waves and spring
Parts of Longitudinal Waves: Compression: place where particles are closest together Rarefaction: place where particles are furthest apart
Longitudinal Particle Motion Particles or energy moves parallel to wave motion
Check for Understanding… 2.A wave is transporting energy from left to right. The particles of the medium are moving back and forth in a leftward and rightward direction. This type of wave is known as a ____. a. mechanical b. electromagnetic c. transverse d. longitudinal
Which Type of Wave Is This? http://campus.pari.edu/radiosky/lessons/lesson1/act03.shtml
Properties of Waves Amplitude – height above or below rest Larger amplitude = more energy
Wavelength= distance between any two corresponding locations. Usually measured in one of three ways: crest to next crest trough to next trough from the start of a wave cycle to the next starting point
Frequency: number of waves in given amount of time higher frequency = more energy Hz = Hertz
High or Low Frequency?
Mechanical vs. Electromagnetic Mechanical waves need a medium Electromagnetic waves can travel through empty space or a medium
Vacuum Vacuum is space that is devoid of matter. The word stems from the Latin adjective vacuus for "vacant" or "void".
All waves can be categorized as Mechanical Travels through some sort of matter Example: sound travels through air, water, solids but cannot travel through a vacuum (an empty space) Electromagnetic Can travel through vacuum (empty spaces) Example: microwaves Light waves Radio waves
Let’s make waves…
Transverse or Longitudinal
Transverse or Longitudinal
Transverse or Longitudinal
Transverse or Longitudinal
Transverse or Longitudinal
Transverse or Longitudinal
Transverse or Longitudinal
Transverse or Longitudinal
Transverse or Longitudinal
Transverse or Longitudinal
Transverse or Longitudinal