Science
Strand IV
Use Scientific Knowledge from the Physical Sciences in Real-World Contexts

 

Science/Strand IV
Content Standard 4
All students will describe sounds and sound waves; explain shadows, color, and other light phenomena; measure and describe vibrations and waves; and explain how waves and vibrations transfer energy. (Waves and Vibrations)

 

Science/Strand IV/Content Standard 4
Middle School

 

Science/Strand IV/Content Standard 4/Middle School
Benchmark 1
Explain how sound travels through different media.

Benchmark Clarification

Sound energy is transferred when vibrating molecules hit other molecules, causing the other molecules to move and transferring energy. Since sound energy is transferred through matter, sound needs a medium to be transmitted. Sound cannot travel through a vacuum (absence of matter).

In a gas, the molecules are far apart with unrestricted motion, which results in a slower transmission of sound waves. In a liquid, the molecules are closer together than in a gas, which allows sound to travel faster.

In a solid, the molecules are tightly packed together and more molecules bounce off each other and return to their original position, which allows an even faster transmission of sound.

Students will:

  • Describe the difference in the transmission of sound through different media (solids, liquids, and gases)

Key Concept / Real World Context / Instructional Example / Assessment Example / Resources

 

Science/Strand IV/Content Standard 4/Middle School/Benchmark 1
Key Concept
Media:

  • solids
  • liquids
  • gases

Vacuum

 

Science/Strand IV/Content Standard 4/Middle School/Benchmark 1
Real World Context
Sounds traveling through solids:

  • glass windows
  • strings
  • the Earth

Sound traveling through liquids:

  • dolphin and whale communication

Sound traveling through gases:

  • human hearing
  • sonic booms

 

Science/Strand IV/Content Standard 4/Middle School/Benchmark 1
Instructional Example

Benchmark Question: How does sound travel through different media?

Focus Question: How does sound travel differently in solids and gases?

The teacher might let students experiment by holding vibrating objects against various parts of their heads (e.g., chin, jawbone) to discover that sounds may reach the ear through solid parts of the body (e.g., bones). Students will discuss why, historically, Native Americans put their ears to the ground to listen for hoof beats. Students will discuss possible advantages for animals that live underground.

  • Students will work in small groups and conduct the following investigations: Place a vibrating object (watch, tuning fork, music box, metronome, buzzer) in the center of a table. Try to hear its sound from a meter away
  • Rest one end of a meter stick on the vibrating object
  • Take turns placing an ear against the other end (Students should hear the sound more clearly)
  • Place an ear on top of a table and listen to the vibrating object
  • Students will answer in writing the question, “Does the medium affect the quality of the sound that is produced?” “How?”

Constructing: (SCI.I.1.MS.1).

Reflecting: (SCI.II.1.MS.5).

 

Science/Strand IV/Content Standard 4/Middle School/Benchmark 1
Assessment Example

After students have described the differences in the particles composing solids, liquids, and gases and have examined several musical instruments, they will work in small groups and conduct an investigation that answers the question, “How is sound transmitted by a telephone?”

Each group will make a cup phone consisting of two plastic cups and a piece of string held between the cups.

Students will take turns and whisper to one another from a fixed distance. One student will speak into one cup while another student listens for the first student’s voice in the other cup. Students will test different distances.

Each student will complete a lab report that includes answers to the following questions:

1. How is sound transmitted from one cup to the other?

2. Why is sound not transmitted when the string is held by one of the students?

3. What is the difference in transmission through different mediums such as air vs. string?

Students should include the following terms in their writings: particles or molecules of matter, vibration, and collisions between particles.

(Give students rubric before activity.)

Scoring Rubric

Criteria

Apprentice

Basic

Meets

Exceeds

Correctness of explanation

Explains how a cup phone works using the term “vibration” but does not connect particles and collisions to that vibration.

Explains how a cup phone works using the term “vibration” and connects particles or collisions to that vibration.

Explains how a cup phone works using the three criteria (terms from the assessment).

Explains how a cup phone works using the three criteria (terms from the assessment) and explains conditions that would prevent the cup phone from working and the reasons why.

 

Science/Strand IV/Content Standard 4/Middle School/Benchmark 1
Resources

Webliography.
http://mtn.merit.edu/mcf/SCI.IV.4.MS.1.html

Primarily Physics. AIMS.
http://wwws.aimsedu.org/aimscatalog/default.tpl

Sound/Light & Color. Bill Nye Video. Disney Educational (800/295-5010).

Sound waves through solid objects.
http://www.mcrel.org/whelmers/whelm67.asp “Bells in Your Ears”

Sound waves through gases.
http://www.mcrel.org/whelmers/whelm11.asp “Straw Oboes”