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 2
Explain how echoes occur and how they are used.

Benchmark Clarification

Echoes occur when sound waves are reflected (bounced off) a large object. The absence of an echo means the sound waves are absorbed and not reflected back to the ear or the reflecting object is too close to produce an echo. The controlling of echoes (reflected sound) in a room or building is called acoustics.

Echoes have many uses. With sonar, a sound wave is reflected back and received by a receiver. By using this device one can measure how far an object is from the sonar device. Sonar is used by bats to locate objects. Sonar is also used in medicine (ultrasound) and in recreation (fish-finders).

Students will:

  • Explain how echoes occur
  • Describe how echoes are used.

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

 

Science/Strand IV/Content Standard 4/Middle School/Benchmark 2
Key Concept

  • echo
  • sonar
  • reflection

 

Science/Strand IV/Content Standard 4/Middle School/Benchmark 2
Real World Context
Echoes in rooms:

  • acoustics
  • outdoors

Practical uses of echoes:

  • navigation by bats and dolphins
  • ultrasound imaging
  • sonar

 

Science/Strand IV/Content Standard 4/Middle School/Benchmark 2
Instructional Example

Benchmark Question: How do echoes occur and how are they used?

Focus Question: How can an echo be heard when a sound is made in an echo-producing place (hallway, stairwells, gym, auditorium, etc.) around the school?

Take students on a field trip to an echo-producing place in or around school. Once in place, students need to produce an echo by clapping two wooden boards together and should note the following: the distance from the reflecting surface, the type of reflecting surface, and any objects that might interfere with the soundŐs reflection (See Benchmark Clarification). Discuss what conditions are needed to produce an echo.

Constructing: (SCI.I.1.MS.1), (SCI.I.1.MS.3), (SCI.I.1.MS.4).

Reflecting: None.

 

Science/Strand IV/Content Standard 4/Middle School/Benchmark 2
Assessment Example

Students will sketch and label their location in a setting where an echo was produced. The following should be noted for each location: distance from the reflecting surface, the type of reflecting surface, and any objects that might interfere with the sound reflection. Students will then present and explain this information to the teacher.

(Give students rubric before activity.)

Scoring Rubric

Criteria

Apprentice

Basic

Meets

Exceeds

Accuracy of explanation

Identifies some of the conditions needed to produce an echo and explanation is incomplete.

Identifies and explains conditions needed to produce an echo or simply identifies conditions.

Identifies and explains all conditions needed to produce an echo (appropriate distance, reflecting sound waves, and appropriate reflecting surface).

Identifies and explains all conditions needed to produce an echo (appropriate distance, reflecting sound waves, and appropriate reflecting surface) and determines that the distance must be greater than seventeen meters.

 

Science/Strand IV/Content Standard 4/Middle School/Benchmark 2
Resources

Bats Incredible. AIMS.
http://wwws.aimsedu.org/aimscatalog/default.tpl

Weisler, Jules. Physical Science Worktext.
http://amscopub.com/