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Chapter 14 Vibrations and Waves

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VIBRATIONS AND WAVESVocabulary Review

Write the term that correctly completes the statement. Use each term once.

amplitude longitudinal wave transverse wave

antinode node trough

crest period wave

frequency periodic motion wavelength

interference refraction

1. _________________________ The time needed for an object to complete one full cycle of simple harmonic motion is the ____ .

2. _________________________ ____ occurs when more than one wave moves through the same medium at the same time.

3. _________________________ When waves are superposed, any point that does not experience displacement is a(n) ____ .

4. _________________________ A disturbance that carries energy through matter or space is a(n) ____ .

5. _________________________ A wave in which the disturbance is parallel to the direction of travel is a(n) ____ .

6. _________________________ The maximum distance an object in simple harmonic motion moves from equilibrium is called the ____ .

7. _________________________ The lowest point of a transverse wave is the ____ .

8. _________________________ The shortest distance between two points where the wave pattern repeats is the ____ .

9. _________________________ Any motion that repeats in a regular cycle is called ____ .

10. _________________________ When two waves interfere constructively, the point with the greatest displacement is called the ____ .

11. _________________________ A(n) ____ travels in a direction perpendicular to its displacement.

12. _________________________ The number of complete oscillations a wave makes each second is the ____ of the wave.

13. _________________________ ____ refers to the change in direction waves experience at the boundary between two different media.

14. _________________________ The highest point of a transverse wave is the ____ .

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SECTION 1 Periodic MotionIn your textbook, read about springs and simple harmonic motion.

Answer the following questions. Use complete sentences.

1. According to Hooke’s law, describe a graph of force versus displacement for an elastic spring.

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2. What does the slope of the graph in question 1 represent?

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3. What does the area under the curve in the graph in question 1 represent?

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4. What are the conditions necessary for simple harmonic motion?

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5. What is the relationship between the potential energy and the displacement of an elastic spring?

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6. A mass on a spring is moving in simple harmonic motion. When is the mass’s acceleration the greatest? When is it the least? Why?

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7. Some cars have bumpers that are modified springs. How does this design protect the car in the event of a crash?

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8. How does the mass of the bob on a pendulum affect the pendulum’s period?

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Chapter 14 Vibrations and Waves

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Chapter 14 Vibrations and Waves

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In your textbook, read about pendulums and resonance.

For each statement below, write true or rewrite the italicized part to make the statement true.

9. _________________________ The swing of a pendulum is an example of simple harmonic motion.

10. _________________________ The restoring force on a pendulum bob is inversely proportional to the bob’s displacement.

11. _________________________ The net force on a pendulum at any given moment is opposite the pendulum’s displacement at that moment.

12. _________________________ Resonance occurs when small forces are applied at regular intervals to an oscillating or vibrating object and the amplitude of the object’s oscillation decreases.

13. _________________________ In order to create resonance, the time interval between applications of force must be proportional to the period of oscillation.

14. _________________________ Pegs arranged in a circle on the floor beneath a swinging pendulum will get knocked down because the floor is rotating as Earth rotates.

SECTION 2 Wave PropertiesIn your textbook, read about mechanical waves and measuring waves.

Circle the letter of the choice that best completes the statement.

1. A wave carries ____ through space.

a. matter c. both matter and energy

b. energy d. neither matter nor energy

2. A mechanical wave is different from other types of waves because it requires a(n) ____ .

a. amplitude c. medium

b. wave pulse d. disturbance

3. A wave that moves from left to right, creating an up and down displacement of the medium, is a(n) ____ .

a. matter wave c. longitudinal wave

b. mechanical wave d. transverse wave

4. Sound waves are ____ waves.

a. longitudinal c. surface

b. transverse d. electromagnetic

5. A surface wave is a wave that has characteristics of ____ .

a. a transverse wave c. both transverse and longitudinal waves

b. a longitudinal wave d. neither transverse nor longitudinal waves

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Chapter 14 Vibrations and Waves

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For each statement below, write true or rewrite the italicized part to make the statement true.

6. _________________________ Fluids usually transmit only transverse waves.

7. _________________________ Waves that travel down a rope are longitudinal waves.

8. _________________________ Waves deep under water are longitudinal waves.

9. _________________________ Waves on the surface of the ocean are transverse waves.

10. _________________________ A wave’s amplitude is related to its speed.

Answer the following questions. Use complete sentences.

11. How does wave speed relate to wavelength and period?

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12. Why do some waves have greater amplitudes than others?

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13. What does it mean for points on a wave to be in phase? What does it mean for points on a wave to be out of phase?

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14. What is the relationship between the amplitude of a wave and the rate of energy transfer?

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15. For waves with a constant velocity, what happens to the wavelength if the frequency of the wave decreases?

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SECTION 3 Wave BehaviorIn your textbook, read about wave behavior.

For each statement below, write true or rewrite the italicized part to make the statement true.

1. __________________________ When a wave encounters a boundary, the wave that strikes the boundary is called the incident wave.

2. __________________________ When a wave encounters a boundary, the wave that returns to the original medium is called the refracted wave.

3. __________________________ When a wave from a light, flexible spring passes into a heavier, stiffer spring, almost all of the wave’s energy is reflected back to the light spring.

4. __________________________ When a wave is sent down a spring connected to a wall, none of the energy in the wave is reflected back.

5. __________________________ When interference produces standing waves in a rope, the rope appears to be standing still.

Answer the following questions. Use complete sentences.

6. What happens when a wave moves across a boundary from one medium to another? Consider two springs, one large and one small, joined end-to-end. Describe the wave pulse moving from a large spring into a smaller one. Explain what happens to the energy in the incident wave.

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7. What is the principle of superposition?

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8. Draw a diagram of wave fronts and rays that represents refraction. Label the boundary. Use arrows to show the change in direction.

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In your textbook, read about waves in two dimensions.

Answer the following questions. Use complete sentences.

9. What is a wave front?

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10. When is a wave refracted?

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11. A ray diagram shows the direction of wave motion. What is the normal? What does it show?

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12. What is the angle of incidence? What is the angle of reflection?

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13. What is the law of reflection?

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14. What causes an echo?

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15. What happens when a wave moves from deep to shallow water? How does the frequency change?

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