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

 

Science/Strand IV
Content Standard 1
All students will measure and describe the things around us; explain what the world around us is made of; identify and describe forms of energy; and explain how electricity and magnetism interact with matter (Matter and Energy)

 

Science/Strand IV/Content Standard 1
Middle School

 

Science/Strand IV/Content Standard 1/Middle School
Benchmark 6
Investigate electrical devices and explain how they work, using instructions and appropriate safety precautions.

Benchmark Clarification

Many electrical devices are used in daily life. Examples: door bells, buzzers, light bulbs, toasters, battery-operated toys, and hair dryers.

It is important to follow the instructions for their use and to operate them safely. Grounding is an example of a safety precaution. An object is grounded when a charged object is connected to the ground by a conductor. For example, a lightning rod carries electricity from the top of a barn to the ground so that the barn does not ignite and burn. Surge protectors work as a circuit breaker to protect electrical appliances from an overload of current reaching the appliance.

Students will:

  • Investigate electrical devices and explain how they work by following the flow of energy through a device
  • Determine if the circuit is complete to make the appliance work by reading a flow diagrams , which is often included in an instruction manual.

See Transformations of Energy (SCI.IV.2.MS.3).

Caution:

Taking apart large appliances is dangerous! Residual charges in capacitors can injure students.

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

 

Science/Strand IV/Content Standard 1/Middle School/Benchmark 6
Key Concept
Flow of electricity for energy or information transfer

Safety precautions for using electrical appliances; grounding

Documentation for toys and appliances-wiring diagrams, written instructions

 

Science/Strand IV/Content Standard 1/Middle School/Benchmark 6
Real World Context
Situations requiring assembly, use, or repair of electricity:

  • electrical toys
  • radios
  • simple appliances (i.e., replacing batteries and bulbs)

Connecting electrical appliances:

  • stereo systems
  • TVs and videocassette recorders
  • computers and computer components

 

Science/Strand IV/Content Standard 1/Middle School/Benchmark 6
Instructional Example

Benchmark Question: How do humans use electricity safely?

Focus Question: How do electrical devices work and how are they safely used?

Students will work in small groups and compare characteristics of several working appliances. Characteristics include on/off switches, wires, complete circuits, etc. Have students take apart flashlights, reassemble them to work, and diagram the internal mechanism showing the current flow. Students may bring in small broken appliances from home. In small groups, students will take appliances apart and hypothesize why they are not working.

(Extension: Have an appliance repair person come to class to discuss studentsŐ hypotheses as to why the appliances are not working.)

Note: Remind students that before they work with an electrical appliance, they should disconnect it from the power source. The teacher should instruct students on proper electrical safety procedures.

Constructing: (SCI.I.1.MS.1), (SCI.I.1.MS.2), (SCI.I.1.MS.3).

Reflecting: (SCI.II.1.MS.3), (SCI.II.1.MS.4).

 

Science/Strand IV/Content Standard 1/Middle School/Benchmark 6
Assessment Example

The teacher will give each student a small, broken electrical device (e.g., flashlight, battery-operated toy). The students will list at least four reasons why the device might not be working. The students will list at least two safety precautions that should be taken while fixing the appliance.

Extension: Have students take their writing home and explain to their parents why the electrical device does not work.

(Give students rubric before activity.)

Scoring Rubric

Criteria

Apprentice

Basic

Meets

Exceeds

Accuracy of explanation

Explains fewer than two valid reasons why appliance does not work.

Explains two to three valid reasons why appliance does not work.

Explains four valid reasons why appliance does not work.

Discusses five or more valid reasons why appliance does not work.

Appropriateness of safety precautions

Describes no safety precautions.

Describes one safety precaution.

Describes two safety precautions.

Describes three or more safety precautions.

 

Science/Strand IV/Content Standard 1/Middle School/Benchmark 6
Resources

Webliography.
http://mtn.merit.edu/mcf/SCI.IV.1.MS.6.html

Primarily Physics. AIMS.

Safety procedures.
http://www.consumersenergy.com/