1St Item Specification: Understand That Sound Is Produced and Carried by Molecules

Content Benchmark P.8.C.2

Students know vibrations (e.g. sounds, earthquakes) move at different speeds in different materials, have different wavelengths, and set up wave-like disturbances that spread away from the source uniformly. E/S

1st Item Specification: Understand that sound is produced and carried by molecules.

Depth of Knowledge Level 1

1. Sound is produced when

1. molecules push against each other causing vibrations.
2. molecules release photons of energy.
3. the electrons release light energy.
4. energy is traveling at the speed of light.

1. The human voice is the result of

1. lungs pulling air in through the nose.
2. vibrations in the vocal chords.
3. the placement of the teeth.
4. moist air exiting the lungs.

1. What types of waves are sound waves?

1. Electromagnetic
2. Longitudinal
3. Transverse
4. Radio

1. The unit that measures the intensity of sound is called

1. decibel.
2. Hertz.
3. meter.
4. lumen.

Depth of Knowledge Level 2

1. A sound wave is a longitudinal, mechanical wave; not a transverse electromagnetic wave. This means that

1. particles of the medium move perpendicular to the direction of energy transport.
2. a sound wave transports its energy through a vacuum.
3. particles of the medium regularly and repeatedly oscillate about their rest position.
4. a medium is required in order for sound waves to transport energy.

1. The diagram below shows sound waves traveling away from a vibrating bell. Use the diagram below to answer the following question.

(From

Which of the following factors would impact the speed of the waves?

1. The direction of the wave as it vibrates away from the bell.
2. How hard the bell was struck to initiate the vibrations.
3. Temperature and medium through which the sound is traveling.
4. Whether the bell was made of steel or some other type of metal.

2ndSpecification: Recognize that waves transfer energy differently in different materials.

Depth of Knowledge Level 1

1. How does the air temperature affect the speed of sound waves traveling through the air?

1. As the temperature decreases, the speed increases.
2. As the temperature increases, the speed decreases.
3. As the temperature decreases, the speed decreases.
4. As the temperature increases or decreases, the speed does not change.

1. Sound waves more the fastest through which of the following media?
2. Water
3. Steel
4. Oxygen
5. Oil

1. The speed of sound in air is most affected by

1. gusting winds.
2. volume of air moving.
3. temperature changes.
4. cloud cover.

Depth of Knowledge Level 2

1. A student observes a bell placed in a vacuum jar. After the vacuum jar is evacuated the bell is rung but no sound is heard. The student states that this is because

1. all sound vibrations are reflected in the glass jar.
2. sound vibrations cancel each other.
3. sound vibrations must travel through a medium.
4. the bell ringer does not work in a vacuum.

1. How does the speed of sound in water compare to its speed in air?

1. The speed is slower because the molecules in water are closer to each other.
2. The speed is the same because it is constant in all media.
3. The speed cannot be compared without knowing the temperature.
4. The speed is faster because the molecules in water are closer to each other.

1. Use the figure below to answer the following question.

(From

What happens when sound waves strike the ear drum?

1. Sound waves are absorbed by the eardrum.
2. Sound waves cause the eardrum to vibrate.
3. The walls of the outer ear change shape.
4. The bones of the cranium vibrate.

3rd Item Specification: Identify and describe characteristics of waves: wavelength, frequency, amplitude and speed.

Depth of Knowledge Level 1

1. Use the diagram below to answer the following question.

Line A best describes the wave’s

1. linkage.
2. crest.
3. trough.
4. wavelength.

1. Use the diagram below to answer the following question.

Line A best describes the wave’s

1. trough.
2. period.
3. equilibrium.
4. amplitude.

Depth of Knowledge Level 2

1. Use the diagram below to answer the following question.

Which interval represents one full wavelength?

1. Point A to Point C
2. Point B to Point D
3. Point A to Point G
4. Point C to Point G

1. As a wave travels between two points in a medium, it transfers

1. energy only.
2. massonly.
3. both energy and mass.
4. neither energy nor mass.

4th Item Specification: Identify the causes and effects of the Doppler Effect.

Depth of Knowledge Level 1

1. Which of the following is correct about the Doppler Effect?

1. The effect is observed as waves bend around solid objects.
2. It occurs as waves enter a new medium, such as going from water to air.
3. It is an observed change in pitch when either the sound source or the listener is in motion.
4. It is the change in wavelength as sound waves enter a medium and are reflected at the boundary.

1. Imagine that you are standing on a corner when a fire truck with sirens screeching approaches you. Which of the following is true?

1. As the truck approaches you, the siren’s pitch seems higher to you.
2. The siren’s pitch seems lower to you as the truck approaches.
3. As the truck passes you, the pitch seems to increase in intensity.
4. The siren’s pitch remains lower then higher as it approaches and passes you.

Depth of Knowledge Level 2

1. The reason a fire truck’s siren sounds HIGHER in pitch as it approaches you is because the truck pushes the sound waves together so that the sound wavelengths in front of the truck get shorter. This causes

1. frequency to increase which increases the pitch.
2. velocity to decrease which increases the frequency.
3. frequency to decrease which decreases the pitch.
4. wavelengths to elongate increasing the pitch.

1. The reason a fire truck’s siren sounds LOWER in pitch as it passes by is because the truck pushes the sound waves together so that the sound wavelengths in front of the truck get shorter. This causes

1. frequency to increase which increases the pitch.
2. velocity to decrease which increases the frequency.
3. frequency to decrease which decreases the pitch.
4. wavelengths to elongate increasing the pitch.

5th Item Specification: Understand the relationship between velocity, wavelength, and frequency.

Depth of Knowledge Level 1

1. The frequency of a wave represents the

1. wave amplitude divided by the period of the wave.
2. wave crest in relationship to the wave trough.
3. number of waves to pass a certain point in a given time.
4. loudness of a sound passing through a medium.

1. Wave velocity refers to the

1. product of the wavelength and the frequency.
2. ratio of the wavelength and the frequency.
3. wavelength in meters per second.
4. period of the wave divided by its intensity.

Depth of Knowledge Level 2

1. The wavelength of a wave can be calculated by

1. multiplying the velocity times the frequency.
2. dividing the velocity by the frequency.
3. multiplying the amplitude by the frequency.
4. dividing the frequency by the velocity.

1. The frequency of a wave can be calculated by

1. multiplying the velocity times the wavelength.
2. dividing the velocity by the wavelength.
3. multiplying the amplitude by the wavelength.
4. dividing the frequency by the velocity.

6th Item Specification:Understand the difference between transverse waves and longitudinal waves.

Depth of Knowledge Level 1

1. In TRANSVERSE waves, the wave energy moves

1. parallel to the wave vibrations.
2. perpendicular to the wave vibrations.
3. opposite to the wave vibrations.
4. in the same direction to the wave vibrations.

1. In LONGITUDINAL waves, the wave energy moves

1. parallel to the wave vibrations.
2. perpendicular to the wave vibrations.
3. apart from the wave vibrations.
4. at right angles to the wave vibrations.

Depth of Knowledge Level 2

1. Sound waves are

1. transverse waves because their vibrations are perpendicular to the motion of the wave’s energy transfer.
2. transverse waves because their vibrations are parallel to the motion of the wave’s energy transfer.
3. longitudinal waves because their vibrations are perpendicular to the motion of the wave’s energy transfer.
4. longitudinal waves because their vibrations are parallel to the motion of the wave’s energy transfer.

1. Electromagnetic waves are

1. transverse waves because their vibrations are perpendicular to the motion of the wave’s energy transfer.
2. transverse waves because their vibrations are parallel to the motion of the wave’s energy transfer.
3. longitudinal waves because their vibrations are perpendicular to the motion of the wave’s energy transfer.
4. longitudinal waves because their vibrations are parallel to the motion of the wave’s energy transfer.

Constructed Responses P.8.C.2

1. Sound is a form of energy that is transmitted through vibrations.

1. Describe how sound waves are affected by their frequency and the medium through which the sound wave passes.

1. A science fiction film shows an explosion in space that is heard by the space travelers on board a spaceship. Critique the correctness of this portrayal providing evidence for your argument.

Content Benchmark P.8.C.2

Students know vibrations (e.g. sounds, earthquakes) move at different speeds in different materials, have different wavelengths, and set up wave-like disturbances that spread away from the source uniformly. E/S

Answers to Sample Test Questions

1. A, DOK Level 1
2. B, DOK Level 1
3. B,DOK Level 1
4. A,DOK Level 1
5. D, DOK Level 2
6. C, DOK Level 2
7. C,DOK Level 1
8. B,DOK Level 1
9. C, DOK Level 1
10. C, DOK Level 2
11. D, DOK Level 2
12. B, DOK Level 2
13. D,DOK Level 1
14. D,DOK Level 1
15. D, DOK Level 2
16. A, DOK Level 2
17. C,DOK Level 1
18. A,DOK Level 1
19. A, DOK Level 2
20. C, DOK Level 2
21. C,DOK Level 1
22. A,DOK Level 1
23. B,DOK Level 2
24. B,DOK Level 2
25. B,DOK Level 1
26. A,DOK Level 1
27. D, DOK Level 2
28. A, DOK Level 2

Constructed Response 3-point Answers and Score Rubrics:

3 points / Response addresses all parts of the question clearly and correctly.
Student response indicates an understanding that frequency is a measure of the regularity of passing sound waves and directly relates to the pitch of the sound, where a greater frequency results in a higher pitch. Student response also indicates sound is a mechanical wave, sound can only travel through a medium, and sound travels fastest through solids, then liquids, then gases.
Sound is not transmitted through the vacuum of outer space. A student example might include bell ringer in a vacuum and observed lack of sound or a similar example.
2 points / Response addresses all parts of the question and includes only minor errors.
1 point / Response does not address all parts of the question.
0 point / Response is totally incorrect or no response provided.