This document is a companion piece to video titled Designing a Fast Pool and is intended as a resource for educators.
Background and Planning Information
About the Video
Anette Hosoi, a mechanical engineer at the Massachusetts Institute of Technology, explains how the knowledge of waves and the energy they transfer is applied to designing competitive pools, such as those built at the London Aquatics Center for the 2012 Summer Olympics.
| 0:00 | 0:12 |
Series opening |
| 0:13 | 0:37 |
Introducing the London Aquatics Center |
| 0:38 | 1:07 |
Olympian Missy Franklin’s opinions on pool design |
| 1:08 | 1:29 |
Definition and examples of waves |
| 1:30 | 1:46 |
Hosoi: How swimmers generate waves |
| 1:47 | 2:08 |
Comparison of Olympic pool designs |
| 2:09 | 2:23 |
Anette Hosoi: How competitive pools dissipate energy |
| 2:24 | 2:40 |
Pool depth at the Aquatics Center |
| 2:41 | 2:55 |
Anette Hosoi and Missy Franklin: Importance of pool depth |
| 2:56 | 3:12 |
Dissipating wave energy with surfaces |
| 3:13 | 3:27 |
Dissipating wave energy with size |
| 3:28 | 3:46 |
Dissipating wave energy with lane lines |
| 3:47 | 4:14 |
Importance of a swimmer’s lane position |
| 4:15 | 4:31 |
Summary of London Aquatics Center features |
| 4:32 | 4:44 |
Closing credits |
Language Support
To aid those with limited English proficiency or others who need help focusing on the video, make transcript of the video available. Click the Transcript tab on the side of the video window, then copy and paste into a document for student reference.
Connect to Science
Framework for K–12 Science Education
- PS3.A: Definitions of Energy
- PS3.B: Conservation of Energy and Energy Transfer
- PS4.A: Wave Properties
Related Science Concepts
- Waves as a mechanical disturbance due to energy input
- Energy
(page 1)
- Energy transfer through waves
- Energy dissipation
- Turbulence in a fluid
- Wave propagation
- Absorption of energy
- Reflection
- Diffraction
Connect to Engineering
Framework for K–12 Science Education
- ETS1.A: Defining and Delimiting Engineering Problems
- ETS1.B: Developing Possible Solutions
- ETS2.A: Interdependence of Science, Engineering, and Technology
Engineering in Action
The engineering problems addressed in Science of the Summer Olympics (SOTSO): Designing a Fast Pool include how to design a competitive pool so that the waves created by the swimmers’ motion interfere as little as possible with their performance. Engineers who help design such structures test how various materials and pool layouts affect the transfer of energy through the water. The main competitive pool at the London Aquatics Center includes an adjustable floor, which, when placed at 3 meters from the water’s surface, allows waves to dissipate before they reach the bottom, rather than reflecting off the pool’s bottom and interfering with the swimmers’ performances. Turbulence is minimized along the pool’s perimeter as the waves generated by swimmers spill into narrow troughs. The lane lines separating the athletes rotate to prevent some of the energy of the waves created by one swimmer from moving into another swimmer’s lane.
Discuss with students how engineers might go about deciding how to design and test a competitive swimming pool and its lanes. Point out that engineers go through a series of design stages, beginning with “blue sky” brainstorming, in which any and all ideas are put on the table for discussion. Thinking “outside the box” is very important at this stage. As they progress through various stages of defining constraints – such as materials, costs, size, and shape, and testing of multiple designs – they eventually limit their ideas to the most practical yet cost- effective solution to the problem. Modeling is an important step in the evolution of engineering designs. Students should understand that models are not perfect representations of every aspect of the design simultaneously, but can give accurate data about certain aspects at any given time. Several different models might be required to accurately represent all aspects of a given system. The development of models and subsequent testing of the finished designs are part of the engineering knowledge-generating activities experimental engineering research and direct trial.
(page 2)
Take Action with Students
Encourage students to explore solutions to a problem related to the width of individual swim lanes using the Design Investigations section of the Inquiry Outline as a guide. As a class, set up constraints within which students will have to test their ideas, such as a limited selection of materials with which to work, and a way in which to generate consistent waves, such as by using an electric fan or by quickly moving a wooden block into and out of a model pool.
Inquiry Outline for Teachers
Encourage inquiry using a strategy modeled on the research-based science writing heuristic. Student work will vary in complexity and depth depending on their grade level, prior knowledge, and creativity. Use the prompts liberally to encourage thought and discussion. Student Copy Masters begin on page 7.
Explore Understanding
To introduce water waves, ask a few volunteers to share their experiences from wave pools, a trip to the beach, a day at the public pool, or even in the bathtub. After students have shared their stories, use prompts such as the following to get students talking about waves in general, how waves transfer energy, and the waves created by swimmers as they move through the water.
- A wave is a….
- Examples of waves include….
- Swimmers create waves when they….
- The waves that form as swimmers swim can affect them by….
- When a wave hits a barrier such as the side of the pool, it….
- When a wave moves through an opening in a swimming pool, it….
Before beginning this lesson, make sure students understand how energy is transmitted through water as a wave. You can demonstrate by placing a shallow, sturdy, transparent container half full of water on a transparency on an overhead projector, then dropping a small rock into the water from a height of no more than 5 cm. Have one or two volunteers describe, in detail, how energy moves outward from the point where the rock hits the water and enters the water. Or, find a video segment of this action on the Internet and show it to students. Compare this demo to the waves created by a swimmer. Also review or explain the terms absorption, reflection, and diffraction as they apply to waves.
Show the video SOTSO: Designing a Fast Pool.
Continue the discussion of waves and how they transfer energy through a medium such as water, as well as how wave energy can interfere with a swimmer, using prompts such as the following:
- When I watched the video, I thought about….
- The expert in the video claimed that _____ because….
- Changing the depth of the water in a pool affects the waves created by….
(page 3)
- The ends and sides of a competitive pool have _____ that ____ the wave energy by….
- Lane lines help dissipate wave energy in a swimming pool by….
- As far as wave energy goes, the best lane to be in during a competition is the _____ lane because….
Ask Beginning Questions
Stimulate small-group discussion with the prompt: This video makes me think about these questions…. Have small groups list questions they have about how to minimize or negate the affects of water turbulence on competitive swimmers. Then groups should choose one question and phrase it in such a way as to be researchable and/or testable. The following are some examples.
- How does water depth affect the turbulence caused by a swimmer?
- How does the surface of a pool’s interior affect water turbulence?
- How do pool troughs reduce water turbulence?
- How do lane lines help dissipate wave energy in a swimming pool?
- How does the width of a swim lane affect how water travels through it?
- What type of swimmer configuration produces the most/least water turbulence along the ends and sides of a pool?
Design Investigations
Choose one of these two options based on your students’ knowledge, creativity, and ability level.
Open Choice Approach (Copy Master page 7)
Small groups might join together to agree on one question for which they will explore the answer, or each small group might explore something different. Students should brainstorm to come up with a procedure they would carry out to answer their question. Be sure students define the constraints within which they are designing. Then work with students to develop safe procedures that control variables and enable accurate measurements. Encourage students with prompts such as the following:
- The variable we will test is….
- The variables we will control are….
- The steps we will follow are….
- To conduct the investigation safely, we will….
Focused Approach (Copy Master pages 8–9)
The following exemplifies how students might investigate how the width of a swim lane affects the waves moving through it. Remind students of their observations of the disturbance made by dropping a rock into a container of water. Ask students questions such as the following to spark their thinking:
- How did the waves move from the point where the rock entered the water?
- What happened as the waves struck the sides of the container?
- How does energy move through the water as a swimmer moves forward?
(page 4)
- Why do you think that the swim lanes in a competitive pool are as wide as they are?
- How would energy move through the water if the lanes were narrower or wider?
- Students might choose to explore their question by simply setting up barriers in a shallow container of water to emulate swim lanes in a competitive pool, and observing how waves move through different sized gaps between the barriers. Or, they might wish to create a scale model based on the actual pool parameters given in the video in which to test their question. Give them free rein in determining how they will explore how the width of a swim lane affects how a wave is transmitted through it. Examining a range of materials might help students refine their question or lead to new questions that they should record for later exploration.
- Encourage students to brainstorm a list of possible ways to test their question before settling on a procedure. Students might find that after an initial attempt they will need to start over with another idea; some might try multiple solutions at the same time. Remind them of the constraints as needed, using prompts such as the following:
- We will use _____ because….
- We might get more consistent waves if we use….
- A better way to observe how the waves move through the model lanes might be to….
- Use prompts such as the following to help students visualize their investigation.
- We will make the model pool by….
- We will test diffraction through at least three different openings by….
- We will create consistent waves by….
- To conduct the investigation safely, we will….
- Students should determine a way to compare the amount of diffraction, or the way the waves spread out as they pass through the different sized openings between the barriers. Use prompts such as the following to spark thinking:
- We will observe diffraction by….
- We will measure the amount of diffraction by….
- Students might continue their investigation by setting up a series of side-by-side lanes, each of which is the same width, and generating single or multiple waves to observe how the waves are diffracted as they go through the lanes.
Make a Claim Backed by Evidence
As students carry out their investigations, ensure that they record their observations either as short videos or as detailed drawings. As needed, suggest ways they might organize their data using tables or graphs. Students should analyze their data and then make one or more claims based on the evidence their data shows. Encourage students with this prompt: As evidenced by… I claim… because….
An example claim regarding lane width might be:
As evidenced by observing water waves pass through three different sized openings, I claim that wider lanes are better than narrow lanes because I observed less wave diffraction (less turbulence) as the waves passed through the largest opening than when they passed through the smaller openings.
(page 5)
Compare Findings
Encourage students to compare their ideas with those of others—such as classmates who investigated the same or a similar question, material they found on the Internet, an expert they chose to interview, or their textbooks. Remind students to credit their original sources in their comparisons. Elicit comparisons from students with prompts such as the following:
- My ideas are similar to (or different from) those of the experts in that….
- My ideas are similar to (or different from) those of my classmates in that….
- My ideas are similar to (or different from) those that I found on the Internet in that….
Students might make comparisons like the following:
My ideas are similar to what I found on the Internet. In researching water waves, I found that experiments with ripple tanks show that waves passing through barriers separated by larger openings diffract less than waves traveling through narrower openings. This supports the idea that swim lanes need to be a certain width to accommodate a swimmer’s motions, as well as to minimize the propagation of waves that could affect a swimmer’s performance.
Reflect on Learning
Students should reflect on their understanding, thinking about how their ideas have changed or what they know now that they didn’t before. Ask groups to give short presentations about their investigations and encourage questions from the audience on the group’s thinking processes, as well as their procedures and results. Encourage reflection, using prompts such as the following:
- I claim that my ideas have changed from the beginning of this lesson because of this evidence….
- My ideas changed in the following ways….
- When thinking about the claims made by the expert, I am confused about….
- One part of the investigation I am most proud of is….
Inquiry Assessment
See the rubric included in the student Copy Masters on page 10.
Incorporate Video into Your Lesson Plan
Integrate Video in Instruction
Visualize a Concept:
Play the video segment from 0:54 to 1:00 without the sound. Ask students to describe what they see and explain how this might affect the swimmers. If needed, focus students’ discussions on the turbulence being created by the swimmers. Have a volunteer who swims competitively explain how different it is swimming alone in a lap pool versus swimming with multiple swimmers in the pool. Or, have a volunteer describe how swimming in still water is different from swimming in choppy waters.
(page 6)
Homework:
Use the video as an engaging reason to learn more about the different strokes used in Olympic competition, and how each stroke affects pool turbulence.
Using the 5E Approach?
If you use a 5E approach to lesson plans, consider incorporating video in these E’s:
Explore: Use the Focused Approach of the Design Investigations section of the Inquiry Outline to support your lesson on wave absorption, reflection, and diffraction.
Extend: Have students view the various lane dividers shown throughout the video and explain what other purposes they may serve. Some students might correctly state that they help keep a swimmer out of another swimmer’s path, and that the different colored segments of the dividers help each swimmer gauge how far he or she still has to go to complete the lap.
Connect to … STEM
Math
Have students do research to find the record times for the top three male and top three female swimmers in the freestyle, backstroke, breaststroke and butterfly events during the past two summer Olympic games—2008 and 2004. Have students graph the data they find, analyze for any trends and/or anomalies, and suggest reasons why those trends or anomalies exist.
Use Video in Assessment
Show students the segment of Missy Franklin’s opinion of the importance of pool depth (2:48–2:54). “The depths of the pool can always make a huge difference… when it”s deeper you feel like you’re going faster.” Then give students the following instruction:
Why would Missy say this? Be sure to use the words waves and turbulence in your answer.
COPY MASTER: Open Choice Inquiry Guide for Students
Science of the Summer Olympics: Designing a Fast Pool
Use this guide to investigate a question about how pool design can reduce turbulence caused by swimmers. Write your lab report in your science notebook.
Ask Beginning Questions
The video makes me think about these questions….
Design Investigations
Choose one question. How can you answer it? Brainstorm with your teammates. Write a procedure that controls variables and makes accurate measurements. Add safety precautions as needed.
- The variable I will test is….
- The variables I will control are….
- The steps I will follow are….
- To conduct the investigation safely, I will….
(page 7)
Record Data and Observations
Record your observations. Organize your data in tables or graphs as appropriate.
Make a Claim Backed by Evidence
Analyze your data and then make one or more claims based on the evidence your data shows. Make sure that the claim goes beyond summarizing the relationship between the variables.
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My Evidence |
My Claim |
My Reason |
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Compare Findings
Review the video and then discuss your results with classmates who investigated the same or a similar question. Or do research on the Internet or talk with an expert. How do your findings compare? Be sure to give credit to others when you use their findings in your comparisons.
- My ideas are similar to (or different from) those of the experts in that….
- My ideas are similar to (or different from) those of my classmates in that….
- My ideas are similar to (or different from) those that I found on the Internet in that….
Reflect on Learning
Think about what you found out. How does it fit with what you already knew? How does it change what you thought you knew?
- I claim that my ideas have changed from the beginning of this lesson because of this evidence….
- My ideas changed in the following ways….
- When thinking about the claims made by the expert, I am confused about….
- One part of the investigation I am most proud of is….
COPY MASTER: Focused Inquiry Guide for Students
Science of the Summer Olympics: Designing a Fast Pool
Use this guide to investigate a question about how the width of a swim lane affects the behavior of the waves that pass through it. Write your lab report in your science notebook.
Ask Beginning Questions
How does lane width affect wave diffraction?
Design Investigations
How can you answer your question? Brainstorm solutions with your teammates. Write a procedure that will enable you to meet the constraints. Add safety precautions as needed. For example, you might construct a model pool with lanes of different widths to see how each affects the waves that travel through it. Use these prompts to help you design and set up your investigation.
(page 8)
- To make the pool, I will….
- To generate consistent waves, I will….
- The variable I will test is….
- The variables I will control are….
- I will compare how each lane affects the waves passing through it by….
- To be safe, I need to….
Record Data and Observations
Organize your data in tables or graphs as appropriate. The table and graph below are examples for different lane widths.
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Relationship Between Lane Width and Amount of Diffraction |
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Diffraction |
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Lane Width |
Trial 1 |
Trial 2 |
Trial 3 |
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_____ cm |
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_____ cm |
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_____ cm |
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COPY MASTER: Assessment Rubric for Inquiry Investigations
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Criteria |
1 point |
2 points |
3 points |
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Initial question |
Question has yes/no answer, is off topic, or otherwise not testable. |
Question is testable but too broad or not answerable by the chosen investigation. |
Question clearly stated, testable, and shows direct relationship to investigation. |
|
Investigation design |
The design of the investigation did not support a response to the initial question. |
While the design supported the initial question, the procedure used to collect data (e.g., number of trials, control of variables) was not sufficient. |
Clearly identified variables that are controlled as needed with steps and trials that result in data that can be used to answer the question. |
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Variables |
Either the dependent or independent variable was not identified. |
While the dependent and independent variables were identified, no controls were present. |
Variables identified and controlled in a way that results in data that can be analyzed and compared. |
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Safety procedures |
Basic laboratory safety procedures were followed, but practices specific to the activity were not identified. |
Some, but not all, of the safety equipment and safe practices needed for this investigation was followed. |
Appropriate safety equipment used and safe practices adhered to. |
|
Observations and Data |
Observations are not made or recorded, and data are unreasonable in nature, not recorded, or do not reflect what actually took place during the investigation. |
Observations are made, but are not very detailed, or data appear invalid or are not recorded appropriately. |
Detailed observations are made and properly recorded and data are plausible and recorded appropriately. |
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Claim |
No claim is made or claim has no relationship to the evidence used to support it. |
Claim marginally related to evidence from investigation. |
Claim is backed by investigative or research evidence. |
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Findings comparison |
Comparison of findings was limited to a description of the initial question. |
Comparison of findings was not supported by the data collected. |
Comparison of findings included both methodology and data collected by at least one other entity. |
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Reflection |
Student reflection was limited to a description of the procedure used. |
Student reflections were not related to the initial question. |
Student reflections described at least one impact on thinking. |