Waves and Sound Worksheet Answers

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Waves and Sound Worksheet Answers

• Section 3
• 1. What is the period of a radio wave that has a
  frequency of 88.0 x106 Hz?

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• 2. What is the frequency of a wave that has a
  period of 5 seconds?

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• 3. What is the frequency if 15 waves passed in
  1.5 seconds?

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• 4. The speed of all electromagnetic waves in
  empty space is 3.00 x 108 m/s. Calculate the
  wavelength of electromagnetic waves emitted at
  the following frequencies
• a. Radio waves at 88.0 x 106 Hz
• b. Visible light at 6.0 x 1014 Hz
• c. X rays at 3.0 x 1018 Hz

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• 5. A piano emits frequencies that range from a
  low of about 28 Hz to a high of about 4200 Hz.
  Find the range of wavelengths in air attained by
  this instrument when the speed of sound in air is
  340 m/s.

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• 6. The red light emitted by a He-Ne laser has a
  wavelength of 633 x 10-9 m in air and
  travels at 3.00 x 108 m/s. Find the frequency of
  the laser light.

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• 7. A tuning fork produces a sound with a
  frequency of 256 Hz and a wavelength in air of
  1.35 m.
• What does this give for the speed of sound in
  air?
• b. What would be the wavelength of this same
  sound in water which sound travels at 1500 m/s?

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• 8. Dogs are able to hear much higher frequencies
  that humans are capable of detecting. If a dog
  whistle has a frequency of 3.0 x 104 Hz, what is
  the wavelength of sound emitted?

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• Honors Addition Pg 486 4

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• Honors Addition Pg 486 5

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• Honors Addition Pg 486 6

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• Section 4
• 1. You need to know the height of a tower, but
  darkness obscures the ceiling. You note that a
  pendulum extending from the ceiling almost
  touches the floor and that its period is 24s.
  How tall is the tower?

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• 2. You are designing a pendulum clock to have a
  period of 1.0 s. How long should the pendulum be?

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• 3. A trapeze artist swings in simple harmonic
  motion with a period of 3.8 s. Calculate the
  length of the cables supporting the trapeze.

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• 4. Calculate the period and frequency of a 3.500
  m long pendulum at the following locations
• The North Pole, where g 9.832 m/s2
• b. Chicago, where g 9.803 m/s2
• c. Jakarta, Indonesia, where g 9.872 m/s2

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Section 5 Finish off the picture by drawing the
reflection. Include the angle in the reflection.
Draw the refracted wave, labeling the normal
line, angle of incidence, and angle of
refraction.
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• Section 6
• 1. What is the velocity of a sound wave on a day
  the temperature is 15.0 ºC?

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• 2. How many seconds will it take to hear an echo
  if you yell toward a mountain 80 m away on a day
  when air temperature is 15.0 ºC?

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• 3. What is the velocity of a sound wave when the
  temperature is -30 ºC?

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• 4. How long would it take to for an observer to
  hear a cow, which is 75 meters away, moo on a
  day that is -30 ºC?

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• 5. What is the wavelength of the cows moo if the
  frequency is 1000 Hz?

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• Honors Addition pg 488 31
• The right-most key on a piano produces a wave
  that has a frequency of 4185.6 Hz. Assuming that
  the speed of sound in air is 343 m/s, find the
  corresponding wavelength.

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• Honors Addition pg 488 35
• An explosion occurs at the end of a pier. The
  sound reaches the end of the pier by traveling
  through three media air, fresh water, and a
  slender handrail made of solid steel. The speed
  of the sound in air, water, and the handrail are
  343, 1482, and 5040 m/s, respectively. The sound
  travels a distance of 125 m in each medium. (a)
  through which medium does the sound arrive first,
  second, and third? (b) after the first sound
  arrives, how much later do the second and the
  third sounds arrive?

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• Section 7
• 1. One foggy morning, Kenny is driving his speed
  boat toward the Brant Point lighthouse at a speed
  of 15.0 m/s as the fog horn blows with a
  frequency of 180.0 Hz. What frequency does Kenny
  hear as he moves?

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• 2. Junior is watching trucks go by and notices
  that they sound different as they approach and
  travel away.
• a. What is the phenomenon called? _______________
• b. If a truck with a frequency of 80 Hz is
  traveling towards Junior with a speed of 27 m/s,
  what frequency does he hear?

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• 3. One way to tell if a mosquito is traveling
  toward or away from you is to listen for the
  Doppler shift. The buzzing sound of a mosquitos
  wings emits a frequency of 1050 Hz.
• a. If you hear a frequency of 1034 Hz, is the
  mosquito coming closer or going away?
  ________________
• b. What frequency would you hear if the mosquito
  was flying away at 3 m/s and the speed of sound
  was 340 m/s?

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• 4. Barney the bumblebee is chasing Betsy. Barney
  is going 2.5 m/s and Betsey is going 4.3 on a day
  that the velocity of sound is 340 m/s. If Betsey
  is making a sound with a frequency of 1540 Hz,
  what frequency does Barney hear?

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• Honors Addition Pg 490 70
• A source is generating circular waves on the
  surface of a lake. The waves have a wavelength
  of 13.4 m and travel outward at a speed of 6.70
  m/s. You are in a boat whose speed it 4.20 m/s
  and heading directly toward the source of the
  waves. What do you observe for the frequency of
  the waves?

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• Honors Addition Pg 490 71
• The security alarm on a parked car goes off and
  produces a frequency of 960 Hz. The speed of
  sound is 343 m/s. As you drive toward this
  parked car, pass it, and drive away, you observe
  the frequency to change 95 Hz. At what speed are
  you driving?

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• Honors Addition Pg 490 71
• The security alarm on a parked car goes off and
  produces a frequency of 960 Hz. The speed of
  sound is 343 m/s. As you drive toward this
  parked car, pass it, and drive away, you observe
  the frequency to change 95 Hz. At what speed are
  you driving?

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• Honors Addition Pg 490 72
• Suppose you are stopped for a traffic light, and
  an ambulance approaches you from behind with a
  speed of 18 m/s. The siren on the ambulance
  produces sound with a frequency of 955 Hz. The
  speed of sound in air is 343 m/s. What is the
  wavelength of sound reaching your ears?

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• Honors Addition Pg 490 74
• A loudspeaker in a parked car is producing sound
  whose frequency is 20,510 Hz. The sound cannot
  be heard because the frequency is too high. When
  the car is moving, however, a person standing on
  the street hears the sound. (a) Is the car
  moving toward or away from the person? Why? (b)
  If the speed of sound is 343 m/s, what is the
  minimum speed of the car if the person is a
  student of normal hearing?