Chapter 14 Notes

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Chapter 14 Notes

• Waves and Energy Transfer Page 326

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Section 1 Wave Properties
Waves transfer energy through matter or
space. Mechanical Waves can travel only through
matter. 2 Types of waves 1) Transverse move
at right angles to the matter through which they
travel water waves. Demo
3
Types of Waves, Continued
2) Compressional move in the same direction as
the matter through which they travel sound
waves. Demo
4
Wave Properties, continued

• Page 331
• Parts of a wave
• I. Transverse Waves have
• A. Troughs low points
• B. Crests high points
• Demo

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II. Compressional Waves Have

• Rarefactions less dense / less compact regions.
• Compressions dense / compact regions.
• Demo

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Wavelength

• For Transverse Waves distance from one crest to
  the next or from one trough to the next.

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II. For Compressional Waves

• Wavelength is the distance from one rarefaction
  to the next or from one compression to the next.
• Frequency number of wavelengths that pass a
  fixed point each second measured in units called
  hertz (Hz) 1 wavelength per sec.

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Amplitude and Energy

• Amplitude distance from rest position to the
  crest or trough in a transverse wave.
• For a compressional wave, amplitude is related
  to how dense the compressions are more dense
  higher amplitude.
• The greater a waves amplitude, the more energy
  it carries.

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Wave Frequency

• Period (T) the time it takes for one wave
  pattern to repeat itself or complete one cycle
  measured in seconds (s)
• Frequency (f) 1 / T measured in cycles per
  second or Hertz (Hz).

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Wave Speed

• Wave Speed wavelength x frequency
• v ? x f
• v
• ? f

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Calculating speed, wavelength and frequency

• To calculate wave speed (v)
• v cover up v
• ? f
  ? f
• Multiply ? and f to calculate wave speed (v).

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Calculating speed, wavelength and frequency,
continued

• To calculate wavelength (?)
• v cover up ? v
• ? f
  f
• Divide v by f to calculate wavelength (?).

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Calculating speed, wavelength and frequency,
continued

• To calculate frequency (f)
• v cover up f v
• ? f
  ?
• Divide v by ? to calculate frequency (f).

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Page 333, Example Problem

• f 262 Hz
• ? 1.29 m
• What is the speed of the wave?
• How long will it take to travels 91.4 m?
• What is the period of the wave?
• a. v ? m/s v ? x f
• v (1.29 m) x (262 Hz) 338 m/s

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FYI (speed of sound in mph)

• (338 m/s) x (1km / 1000m) x (1mile / 1.67km)
• 0.2023952 miles / second
• (0.202 miles / s) x (3600 s / hour)
• 727 miles / hour the speed of sound.

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Example Problem Continued

• d 91.4 m
• v 338 m/s
• t ? s
• t d / v (91.4 m) / (338 m/s) 0.270 s
• c. Period (T) ? s
• f 1 / T T 1 / f
• T 1 / 262 Hz 0.00382s

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Page 335 Do Practice Problems 1 - 7

• a. 343 m/s
• b. 0.00229 s
• c. 0.787 m
• a. 343 m/s
• b. 457 Hz
• c. 0.00219 s

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Practice Problems 3 - 7

• Lower
• 1.50 m/s
• 3.00 m
• 0.600 m/s
• 8.00 m/s

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Section 2 Wave Behavior

• Page 336
• Reflection light waves bouncing off of an
  object.
• Refraction bending light waves in a material,
  such as water, due to the waves slowing down.
• Diffraction bending light waves around an
  object.

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Reflection

• Incident Wave the wave that strikes a boundary.
• Reflected Wave - the wave that bounces off of a
  boundary.

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Interference

• Interference when two or more waves combine to
  form a new wave.
• Constructive the wave amplitudes add together.
• Destructive wave amplitudes subtract from each
  other.
• Standing Waves equal waves traveling in
  opposite directions.

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Nodes

• Places where two standing waves cancel each other
  out by destructive interference (Figure 14-13,
  page 340).
• Antinodes places where two standing waves add
  to each other by constructive interference.

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• Resonance the ability of an object to vibrate
  by absorbing energy.
• Demos
• Assignment Page 346 do Chapter 14 Review
  Problems 32 40 (do only parts a and b for
  problem 38).

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Study Guide Worksheets, pages 79 84 do in
class, keep, grade.

• Page 79 Vocabulary Review
• a Longitudinal wave is the same thing as a
  Compressional wave.
• Page 80 Multiple Choice and True / Rewrite
• Page 81 - True / Rewrite, Matching, Equations.

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Page 82

• Fill-in-the-blanks and diagrams
• NOTE Wave 1 should be labeled with the letter
  D on the top, horizontal double arrow
  c

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Semester Test Review

• Multiple choice (terms)
• Waves
• Wave Pulse
• Wavelength
• Crest
• Rarefaction
• Transverse wave
• Interference (constructive and destructive)

• Wave Speed
• Reflection
• Amplitude
• Node
• Medium
• Diffraction
• Frequency
• Refraction

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Angle of reflection
Normal Angle of incidence
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Wave Equations For Note Card

• Period (T) the time it takes for one wave
  pattern to repeat itself or complete one cycle
  measured in seconds (s)
• Frequency (f) 1 / T measured in cycles per
  second or Hertz (Hz).
• Wave Speed wavelength x frequency
• v ? x f

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Equations For Electricity and Magnetism problems
(12)

• Coulombs Law F k qa x qb
• (page 472) d2
• Electric Field Force / Charge F / q
• (page 482)
• Power P IV
• (Page 510)

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Equations For Electricity and Magnetism problems
(12)

• Magnetic Force F BIL
• (Page 568) Force (N), B Magnetic Field Strength
  in Tesla (T), I Current (A), L Length (m)
• Magnetic Force in moving charges F Bqv
• (Page 572) Force (N), B Magnetic Field Strength
  in Tesla (T), q Charge (C), v velocity (m/s)

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Equations For Electricity and Magnetism problems
(12)

• Voltage between charged plates V E.F. x d
• (Page 491) V (voltage), E.F. electric field
  strength in N/C, d distance between plates in
  meters (m).
• Capacitance C q / V
• (Page 500) C capacitance in farads (F), q
  Charge in Coulombs C , V (voltage)

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Equations For Electricity and Magnetism problems
(12)
Voltage, work and charge V W / q (Page 488)
V(voltage), W work, in Joules (J), q Charge
in Coulombs (C).