8th Grade - Unit 2: Waves

Instructional Sequence

Assessment Types at
This Stage

Assessment Description

Learning Target

Engage

Predictions, Observations, and Initial Exploration: Students’ background knowledge about waves and wave types is assessed.

Students are asked to think about examples of waves from their own lives. Students observe videos that show examples of different waves in everyday life. Students work together to come up with a preliminary definition of the term wave. 

Students should be able to

• Identify at least one type of wave other than waves in water.
• Write down a preliminary definition of the word wave that they will revise throughout the subunit. 

Explore

Observations and Inferences: 

Students investigate wave characteristics to generate ideas—through discussion—about how frequency, wavelength, and amplitude relate to waves.  These initial ideas form the criteria for examining wave characteristics throughout the unit.

Students investigate wave characteristics by generating water waves in clear portable water basins.  Students observe video of waves generated in ripple tanks to explore how frequency and wavelength are related for waves in the same medium. Students observe demonstrations of transverse and longitudinal waves generated using a coiled spring toy. 

Students should be able to

• Design investigations to explore characteristics of water waves.
• Observe different characteristics of water waves generated in a ripple tank. 
• Observe coiled spring demonstrations of transverse and longitudinal waves.
• Describe to the class what they discovered during their observations of waves.

Explain

Reading, Group Discussion, and Written Responses: 

Students work with different wave model animations and interactives to better understand wave characteristics of wavelength, frequency and amplitude. They also read an article about waves and wave characteristics. Students apply information from the animations, interactives, and article to update their definition of the term wave and other key terms associated with waves. 

Students reflect on their observations of waves in the Explore lesson by working with wave model animations and reading an article that helps them to answer the question “What is a wave?”

Students should be able to

• Explore animated models of waves to learn key terms associated with waves. 
• Explain that a simple wave has a repeating pattern with a specific frequency, wavelength, and amplitude.
• Describe the mathematical relationship between frequency and wavelength of a wave traveling at a constant speed. 
• Describe how the energy of a wave is related to the wave’s amplitude and frequency.

Elaborate

Applying Understanding to a New Context: Students apply their ideas (model) from the Explain lesson to a model for ocean surface waves. 

Students observe a video of ocean surface waves and compare what they observe to several animated models for waves. Students are asked to argue whether ocean surface waves are longitudinal, transverse, or have aspects of both types of wave motion. 

Students should be able to   

• Observe a video and animated models of water waves.
• Describe the motion of particles in the medium for different waves.  
• Argue whether ocean waves are longitudinal, transverse, or a combination of both types of wave motion. 

Evaluate

Engaging in Argument from Evidence, Revising a Model, and Connecting Concepts:

Students demonstrate their understanding and evaluate their knowledge of waves and wave characteristics. Using a Peer Feedback protocol, students revise their models. Students revisit the Driving Question Board and Personal Glossary. 

Students come up with their final definition of waves and demonstrate that they can produce simple wave models that show differences in frequency, wavelength, and amplitude. Students explain the relationships between amplitude, and energy of a wave and frequency and energy of a wave. 

Students should be able to 

• Define the term wave and explain that in a simple wave model, waves have a repeating pattern of frequency, wavelength, and amplitude.
• Draw models of waves that demonstrate the relationship between amplitude and energy.
• Draw models of waves that demonstrate the relationship between frequency and energy.
• Draw models that show the difference between a transverse wave and a longitudinal wave.
• Work with a partner to use the Stronger and Clearer routine to get feedback and revise their models.  

Instructional Sequence

Assessment Types at
This Stage

Assessment Description

Learning Target

Engage

Predictions, Observations, and Initial Exploration: Students’ background knowledge about sound waves is assessed. Also, students explore how sound waves can travel through various media.

Students observe a video that demonstrates that sound waves require a medium. Students also build simple telephones to explore how various media affect the quality of sound.

Students should be able to

• Observe that sound waves require a medium to travel from one place to another.
• Explore sound through simple classroom experiments. 
• Design, build, and test a simple telephone. 
• Begin to model sound waves traveling through solids, liquids, and gases. 

Explore

Observations and Inferences: 

In this lesson, students explore different models for sound waves. Students investigate and collect data on how sound travels through different media. Finally, students work with online interactive applications and simulations to explore how the amplitude of a sound wave is related to loudness and how the frequency of a sound wave is related to pitch.  

Students explore different models for sound waves and use this information to rebuild their simple telephones using different materials. In this activity, students use a virtual oscilloscope to collect data about the amplitude and frequency of sounds that travel through their telephones. Students investigate how the frequency and amplitude of sound waves change as they travel through various media. Finally, students work with interactive applications and simulations to explore the relationship between amplitude and loudness of a sound and the relationship between frequency and sound pitch. 

Students should be able to

• Explore particle models and simple mathematical models for sound waves.
• Observe that sound wave characteristics can change as they travel through different media.
• Explore how the amplitude of a sound wave is related to loudness and the frequency of a sound wave is related to pitch.  

Explain

Reading, Group Discussion, and Written Responses: 

Students create a model to explain how sounds can travel from one room to another.  Students read an article about the behavior of sound waves when they interact with matter.  When students have completed the reading, they revisit their preliminary model and revise based on what they have learned. Finally, students add the terms absorption, reflection, and transmission to their Personal Glossary.

Students develop a model to explain how sound can travel from one room to another through a wall. Students then complete a reading about sound waves and use the information from the reading to revise their models. 

Students should be able to

• Explain that sound waves, like all mechanical waves, require a medium. 
• Explain that when sound waves meet a boundary of a new medium, the waves can be reflected, absorbed, or transmitted through the new medium. 
• Explain the relationship between loudness and the amplitude of a sound wave. 
• Explain the relationship between pitch and the frequency of a sound wave. 

Elaborate

Applying Understanding to a New Context: Students explore using sound to send messages using Morse code. Students explore how animals use sound to communicate. 

Students consider how people use sounds to communicate and explore using sound to send messages using Morse code. Students then work with an online interactive to explore how animals use sound to communicate. Students create presentations based on case studies of different animals. 

Students should be able to   

• Explain how they might be able to use sound to send messages in Morse code through a wall. 
• Create a presentation that illustrates how a particular group of animals uses sounds to communicate. 

Evaluate

Engaging in Argument from Evidence, Revising a Model, and Connecting Concepts:

Students demonstrate their understanding and evaluate their knowledge of sound waves. Students revise their Driving Question Board to understand the concepts closely related to the Culminating Project. 

Students evaluate their understanding about sound waves and then begin work on their culminating projects, focusing on using sound waves to communicate through a wall. Students add to and revise their class Driving Question Board and review their own Personal Glossary by adding new writing and images if needed.

Students should be able to 

• Demonstrate their understanding of the basic science of sound waves
• Design a system for using sound to communicate through a wall.
• Develop a model that shows how sound waves travel from the sender to the receiver of the message sent through the wall. Plan for using sound to communicate through various materials.

Instructional Sequence

Assessment Types at
This Stage

Assessment Description

Learning Target

Engage

Predictions, Observations, and Initial Exploration: Student background knowledge about light waves is assessed. 

Students will use Morse code to send a message using light waves to someone who is not in their direct line of sight.  

Students should be able to 

• Observe that light can be used to communicate.
• Send a simple message in Morse code using patterns of light. 
• Observe that light moves in straight line paths.

Explore

Observations and Inferences: 

Students use a flashlight to investigate what happens when light interacts with matter. Students explore different models for the behavior of light when it is reflected, transmitted, and absorbed. 

Students investigate whether light is reflected, transmitted, or absorbed by different materials. Students are presented with a series of videos that model the behavior of light when it is transmitted, refracted, reflected and absorbed. Students return to the digital interactive activities they have worked with in Subunits 1 and 2 to explore how amplitude and frequency are related to visible light. Finally, students have a chance to revise their models based on what they have learned. 

Students should be able to

• Conduct an investigation to explore light transmission, reflection, and absorption as light interacts with different materials. 
• Draw models to represent transmission, refraction, reflection, and absorption of light waves. 
• Explore how the amplitude of light waves is related to brightness (intensity) and that the frequency of visible light is related to color. 

Explain

Reading, Group Discussion, and Written Responses: 

Students read an article about light waves. Students apply information from the article to model light waves traveling from a sender to a receiver. 

Students apply information from an article to analyze their observations from the Explore lesson. Students develop a model to explain how they can control the amplitude and path of a light wave emanating from a flashlight.

Students should be able to

• Describe that electromagnetic energy travels in waves that do not require a medium.  
• Model the behavior of light when it is reflected, transmitted, and absorbed by matter
• Explain that reflection of light occurs when light bounces back from a surface that it cannot pass through. If the surface is very smooth, the reflected light forms an image.
• Explain that transmission of light occurs when light passes through matter. As light is transmitted, depending on the angle of incidence, it may pass straight through matter or it may be refracted.
• Explain that absorption of light occurs when light transfers its energy to matter rather than being reflected or transmitted by matter. 

Elaborate

Applying Understanding to a New Context: Students apply their ideas (model) from the Explain lesson as they explore how electromagnetic waves can be used to transmit information quickly. 

Students watch two videos about electromagnetic waves as preparation for two activities. In the first activity, students explore how digital images can be stored as codes. Students then work together as a class on an activity that helps them to understand how radio wave signals can be used to send data out into the solar system and back. 

Students should be able to   

• Begin to learn about how radio waves can be used to transmit and receive information. 
• Explore  how computers store information about images in pixels.
• Begin working on their culminating projects. 

Evaluate

Engaging in Argument from Evidence, Revising a Model, and Connecting Concepts:

Students demonstrate their understanding and evaluate their knowledge of sound and light waves. Students revise the Driving Question Board to better understand the concepts closely related to the Culminating Project. Students work on their Group Culminating Project and Individual Culminating Project.

 

Students evaluate their own understanding of light waves. Students revise the Driving Question Board to include new ideas regarding light waves. Students work on their Culminating Project by designing and testing methods for using sound and/or light waves to communicate. Students then complete their Group Culminating Project and Individual Culminating Project.

Students should be able to 

• Evaluate their own understanding of light waves and how they behave. 
• Complete the design and testing for the group part of their culminating projects. 
• Complete the individual part of their culminating projects.
• Receive feedback on their project and make revisions based on the feedback.

Desired Results

Overview
In this unit, students investigate the characteristics of waves and design a simple communication system that uses light and/or sound waves. Throughout the unit, students learn a simple wave model that describes waves as having a regular, repeating, pattern with a specific wavelength, frequency, and amplitude. Students learn that waves can transmit both energy and information from one place to another. The Science and Engineering Practices of Using Mathematics and Computational Thinking, Developing and Using Models, and Analyzing and Interpreting Data are emphasized. The Crosscutting Concepts of Cause and Effect, Patterns, and Structure and Function help students understand how scientists interpret the data they collect using scientific tools. 

Project Tasks

Connections to the Culminating Project Lift-Off: Students watch videos about hearing and vision and develop simple models for how we see and hear. Students also answer Reflection Questions designed for students to draw upon their prior knowledge about waves. 

Connections to the Culminating Project Subunit 1: Students develop a model explaining characteristic properties of waves and what happens to the energy of a wave when these characteristics change.

Connections to the Culminating Project Subunit 2: Students use available materials to test out various methods of communication through a wall using  sound waves.

Connections to the Culminating Project Subunit 3: Students weigh the benefits and drawbacks of using sound or light waves for communication. 

Estimated length of project: 265 minutes

ESTABLISHED GOALS

MS-PS4-1. Use mathematical representations to describe a simple model for waves that includes how the amplitude of a wave is related to the energy in a wave. [Clarification Statement: Emphasis is on describing waves with both qualitative and quantitative thinking.] [Assessment Boundary: Assessment does not include electromagnetic waves and is limited to standard repeating waves.]

MS-PS4-2. Develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials. [Clarification Statement: Emphasis is on both light and mechanical waves. Examples of models could include drawings, simulations, and written descriptions.] [Assessment Boundary: Assessment is limited to qualitative applications pertaining to light and mechanical waves.]

MS-ETS1-3. Analyze data from tests to determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a new solution to better meet the criteria for success.
 

MS-ETS1-4. Develop a model to generate data for iterative testing and modification of a proposed object, tool, or process such that an optimal design can be achieved. 

NGSS Lead States. 2013. Next Generation Science Standards: For States, By States. Washington, DC: The National Academies Press.

ESSENTIAL QUESTION

How do we use waves to communicate?

Students will be able to independently use their learning to

• Apply their understanding of wave behavior to design a simple communication system.
• Provide a detailed analysis of data from different systems and  identify the best characteristics of each solution.

Students will know: 

• Waves have a regular, repeating, pattern with a specific wavelength, frequency, and amplitude.
• How amplitude and frequency are related to the energy carried by a wave. 
• Sound waves that transmit more energy and have a greater amplitude, sound louder, and can carry longer distances or travel through a medium that is denser than sound waves transmitting less energy.
• Electromagnetic waves vary in wavelength and frequency. Longer wavelength electromagnetic waves have lower frequencies, and shorter wavelength waves have higher frequencies. 
• Sunlight contains the complete range of wavelengths of electromagnetic waves, and visible light consists of a very narrow range of wavelengths that people can see.
• Reflection of light occurs when light bounces back from a surface that it cannot pass through. If the surface is very smooth, the reflected light forms a reflection. 
• Light transmission occurs when light passes through matter. 
• When light is absorbed, some of its energy can be transferred to matter rather than be reflected or transmitted by matter.  

Evidence

Assessment Evidence

PERFORMANCE TASK: Power Outage Communication System

Group Culminating Project: Using materials the teacher provides, students will design, build, and test systems of communication that use sound and/or light waves. Student solutions must address the benefits and drawbacks of their plan given varying circumstances. The Group Culminating Project will be assessed using the Science Content Rubric. The Group Culminating Project will also be assessed using the Oral Presentation Rubric. Select one area from this rubric for your students to focus on during their presentations.

Individual Culminating Project: Each student writes a report explaining the science behind the communication systems.

The Individual Culminating Project will be assessed using the entire Science Content Rubric.

The Individual Culminating Project will also be assessed using the Science and Engineering Practices Rubric, with a focus on the following rows:

• Analyzing and Interpreting Data
• Using Mathematical and Computational Thinking
• Developing and Using Models

Learning Plan

Subunit 1

In the course of this subunit, students investigate the characteristics of waves and work toward generating a definition for the term wave that they revise throughout the subunit. During their investigations, students collect and analyze data as they manipulate the characteristics of water waves to determine how to control a wave’s characteristics. Students develop initial ideas around the relationship between the amplitude of a wave and the amount of energy transmitted through a wave. 

Subunit 2

In this subunit, students investigate the characteristics of sound waves to figure out how to use sound waves to communicate through  a wall. During their investigations, students collect and analyze data as they study how sound wave characteristics are affected as they travel through different media. Students develop models of sound waves that show how the particles of the medium move as the energy is transferred. 

Subunit 3 

Students investigate electromagnetic energy which can be modeled as waves that do not require a medium. Students explore the properties of visible light waves as a means of communicating. 

Unit Map

Waves

Essential Question: How do we use waves to communicate?

Lift-Off and Introduction to the Culminating Project

 Subunit 1: What is a wave?

What is a wave?

Engage • Explore • Explain • Elaborate • Evaluate

Subunit 2: Sound Waves

What are sound waves and how do they behave?

Engage • Explore • Explain • Elaborate • Evaluate

Subunit 3: Light Waves

What are light waves and how do they behave? 

Engage • Explore • Explain • Elaborate • Evaluate

Group Culminating Project

Design a Communication System

Individual Culminating Project

Communication System Report

Course Concepts

+ Foundational Crosscutting Concepts: These concepts are foundational to the understanding of middle school science. These concepts are present throughout the course. Students are expected to continue to apply their knowledge of the concepts to subsequent relevant projects. 

* Focal Crosscutting Concept: This concept is called out consistently in the Teacher Edition and once per subunit in the Student Book. Students consider the unit project through the lens of this Crosscutting Concept. 

Crosscutting Concept

Unit 1: Motion in the Universe

Unit 2: Waves

Unit 3: Life on Earth

Unit 4: Natural Selection

Patterns

+

+

*

Cause and Effect

+

*

+

+

Scale, Proportion, and Quantity

+

+

Systems and Systems Models

*

Energy and Matter

Structure and Function

+

*

Stability and Change

+

Science and Engineering Practices: 

+ Foundational Science and Engineering Practices: These practices “carry forward” through the course. Students focus on one of these practices per unit and are then expected to continue to apply that knowledge to subsequent relevant projects. 

* Focal Science and Engineering Practice: This practice is called out consistently in the Teacher Edition and once per subunit in the Student Book. Students use this practice to complete the unit project. 

Science and Engineering 

Practices

Unit 1: Motion in the Universe

Unit 2: Waves

Unit 3: Life on Earth

Unit 4: Natural Selection

Asking Questions and Defining Problems 

*

+

Developing and Using Models 

+

*

+

Planning and Carrying Out Investigations 

+

Analyzing and Interpreting data

+

+

Using Mathematics and Computational Thinking

+

*

Constructing Explanations and Designing Solutions

+

+

Engaging in Argument from Evidence

+

*

Obtaining, Evaluating, and Communicating Information

+

MS-PS4-1 

Use mathematical representations to describe a simple model for waves that includes how the amplitude of a wave is related to the energy in a wave. [Clarification Statement: Emphasis is on describing waves with both qualitative and quantitative thinking.] [Assessment Boundary: Assessment does not include electromagnetic waves and is limited to standard repeating waves.]

MS-PS4-2

Develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials. [Clarification Statement: Emphasis is on both light and mechanical waves. Examples of models could include drawings, simulations, and written descriptions.] [Assessment Boundary: Assessment is limited to qualitative applications pertaining to light and mechanical waves.]

MS-ETS1-3

Analyze data from tests to determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a new solution to better meet the criteria for success.

MS-ETS1-4 

Develop a model to generate data for iterative testing and modification of a proposed object, tool, or process such that an optimal design can be achieved.

Misconceptions 

Accurate Concept

Energy is not transferred by sound. Sound is not related to energy.

From American Association for the Advancement of Science (AAAS) Misconceptions (http://assessment.aaas.org/misconceptions/2/EG/369/RGM047)

Sound transfers energy through matter as the molecules that make up the matter collide with one another.

Misconceptions 

Accurate Concept

Energy is not transferred by sound. Sound is not related to energy.

From AAAS Misconceptions (http://assessment.aaas.org/misconceptions/2/EG/369/RGM047)

Sound transfers energy through matter as the molecules that make up the matter collide with one another.

Misconceptions 

Accurate Concept

Sounds can travel through empty space (a vacuum). Therefore, energy can be transferred by sound in outer space (Hapkiewicz, 1992).

From AAAS Misconceptions (http://assessment.aaas.org/misconceptions/0/NG/369/RGM014)

A sound wave needs a medium through which it is transmitted. (MS-PS4-2)

As sound travels through matter, the matter moves along with the sound wave.

From AAAS Misconceptions (http://assessment.aaas.org/misconceptions/2/RGM016/384)

As sound moves through matter, particles that make up matter vibrate and collide with each other.  As the particles collide, energy is transferred from one particle to the next. Any sound can cause the matter in a medium to vibrate, and these vibrations transfer energy from the sound source to another location.

Only loud sound can transfer energy.

From AAAS Misconceptions (http://assessment.aaas.org/misconceptions/0/RG/370/RGM050)

As sound moves through matter, particles that make up matter vibrate and collide with each other. As the particles collide, energy is transferred from one particle to the next. Any sound can cause the matter in a medium to vibrate, and these vibrations transfer energy from the sound source to another location.

Misconception 

Accurate Concept

Light cannot travel through space. A medium is required to transfer energy by radiation. 

From AAAS Misconceptions 

(http://assessment.aaas.org/misconceptions/2/RGM045/398)

Energy can be transferred by light in outer space because light does not require a medium. but energy cannot be transferred by sound because sound requires a medium such as air to carry it.

From AAAS Concepts (http://assessment.aaas.org/items/0/CL/360/RG068003#/0)