HW 1-16

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Ch. 25 Waves

• HW 1-16

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Ch. 25.1-25.2

• 1. A vibration causes a wave and a wave spreads
  out through space.
• 2. The period would be 1 second.
• 3. The pendulum would take 1.5 seconds.
• 4. A longer period is produced by a longer
  pendulum
• 5. A sine curve represents the periodic motion of
  a wave and demonstrates simple harmonic motion of
  the particles that transmit the wave energy.

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Ch. 25

• 6. Parts of a wave
• Amplitude equals the maximum displacement from
  the point of equilibrium
• Crest is the high point on a wave
• Trough is the low point on a wave
• Wavelength is the distance from one point to the
  next identical point on a wave
• 7. Period is the time it takes for one complete
  cycle of a wave (seconds) the frequency is the
  number of waves that pass a single point per unit
  time or the number of vibrations per second
  (Hertz)

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Ch. 25

• 8. No. The medium does not move along with the
  wave. The wave energy passes through the medium
  and is carried by the disturbance that travels
  through.
• 9. The speed of a wave is calculated by
  multiplying frequency by wavelength.
• 10. As the frequency of a sound increases, the
  wavelength decreases (inverse relationship)

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Ch. 25

• 11. Difference between transverse and
  longitudinal waves
• A transverse wave is produced by a vibration that
  is perpendicular to wave travel.
• A longitudinal wave is produced by a vibration
  that occurs parallel to or is in the same
  direction as wave travel.

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Ch. 25

• 12. Wave interference occurs when two or more
  waves share the same space and the amplitude of
  the wave either increases or decreases.
• Constructive interference when the interference
  of two or more waves produce a wave with a larger
  amplitude
• Destructive interference when the interference
  of two or more waves produce a wave with a
  smaller amplitude (sometimes the waves will
  completely cancel each other out)
• 13. Interference is a property shared by all
  types of waves.

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Ch. 25

• 14. A standing wave is a wave that appears to
  stay in one place. A standing wave forms when
  two waves identical in frequency, wavelength and
  amplitude moving in opposite directions interfere
  (incident and reflected waves)
• Antinodes form by constructive interference
  (waves build in phase) and nodes form by
  destructive interference (waves cancel out
  completely and are out-of-phase)

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Ch. 25

• 15. The Doppler Effect is an apparent shift in
  frequency caused by the motion of a source of a
  wave relative to an observer or vice-versa. As
  the source of a wave approaches a receiver, the
  receiver will encounter only an increase in wave
  frequency.
• 16. The Doppler Effect occurs for all waves, but
  is most recognizable for sound waves and light
  waves.

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25.2 Wave Description

• The Parts of a Wave

A weight attached to a spring undergoes simple
harmonic motion. A marking pen attached to the
bob traces a sine curve on a sheet of paper that
is moving horizontally at constant speed. A sine
curve is a pictorial representation of a wave.