Pendulum Time

Build Materials (For each team)

Required Materials

• String
• Rubber balls, golf balls, ping pong balls, or ball, fishing weight (to use as pendulum weight)
• Pencil
• Aluminum foil
• Paper cups
• Paper clips
• Wire
• Plastic or paper plates
• Glue
• Pipe cleaners
• Pvc piping
• Cardboard
• Paper
• Velcro

Materials

• Clock design
• Stopwatch

Process

Teams test their clock design by demonstrating how the pendulum swings at a faster and slower speed. They will need to be able to record time with their clock and set up their own scale or chart to keep track of the pendulum movements. Use a stopwatch to see how many swings of the pendulum occur in 10 seconds. They will also need to speed up or slow down their clock.  (Hint: adjusting the length of string attached to the pendulum might assist with this task.)

Design Challenge

You are part of a team of engineers who have been given the challenge of building a working clock based on a pendulum.  You’ll need to be able to set the clock at two speeds, and will have to figure out how to adjust the materials you are using to make the clock run faster and slower.

Criteria

• Must be able to set the clock at two speeds.

Constraints

• Use only the materials provided.
• Teams may trade unlimited materials.

1. Break class into teams of 3-4.
2. Hand out the Pendulum Time worksheet, as well as some sheets of paper for sketching designs.
3. Discuss the topics in the Background Concepts Section. To introduce the lesson, consider asking the students how important it is to have a way to accurately measure time. Ask them to observe all the different types of clocks and time measuring devices they have at school and at home.
   Explain that a pendulum is relatively simple, and consists of only a few components: a length of string or wire, a bob or some type of weight, and a fixed point where it is attached to a solid object.  A string may swing in various directions, but for the clock, they will want to fix it to something, or use another material to keep the motion along a single plane — back and forth, not wobbling.
4. Review the Engineering Design Process, Design Challenge, Criteria, Constraints and Materials.
5. Provide each team with their materials.
6. Explain that students must design and build a working clock based on a pendulum. They will need to be able to set the clock at two speeds, and will have to figure out how to adjust the materials they are using to make the clock run faster and slower.
7. Announce the amount of time they have to design and build (1 hour recommended).
8. Use a timer or an on-line stopwatch (count down feature) to ensure you keep on time. (www.online-stopwatch.com/full-screen-stopwatch). Give students regular “time checks” so they stay on task. If they are struggling, ask questions that will lead them to a solution quicker.
9. Students meet and develop a plan for their clock. They agree on materials they will need, write/draw their plan, and present their plan to the class. Teams may trade unlimited materials with other teams to develop their ideal parts list.
   Tell students that their clock doesn’t need to be perfect, but does need to be able to measure time fairly consistently.  They can keep a chart or measurements of the “period of the pendulum” — which is the amount of time that it takes a pendulum to complete one full back-and-forth swing.
10. Teams build their designs. They should be sure to measure the length of the string they plan to use to attach their weight in order to form a pendulum. They will need to keep track of this when they are adjusting the speed at which their pendulum moves. They may wish to weigh their pendulum weight as well, to help them set their clock to work at two different speeds
11. Teams test their clock design by demonstrating how the pendulum swings at a faster and slower speed. They will need to be able to record time with their clock and set up their own scale or chart to keep track of the pendulum movements. Use a stopwatch to see how many swings of the pendulum occur in 10 seconds. They will also need to speed up or slow down their clock. (Hint: adjusting the length of string attached to the pendulum might assist with this task.)
12. As a class, discuss the student reflection questions.
13. For more content on the topic, see the “Digging Deeper” section.

Variations

For younger students, simplify the lesson by having the string/wire taped or tied to a chair frame, and just have them observe and record with a stopwatch the constancy of the pendulum motion.

For older students, require a gear system or escapement, so the pendulum is a working part of a larger mechanism.

Extension Activity

Have students build a working metronome that can keep a beat at equal time intervals. Have students explore the concept of isochronism.

Student Reflection (engineering notebook)

1. How similar was your original design to the actual clock your team built?
2. If you found you needed to make changes during the construction phase, describe why your team decided to make revisions.
3. Was your clock able to measure time at two different speeds? What measurement scale did you devise to measure time with your clock?
4. Which clock that another team made was the most effective or interesting to you? Why?
5. Do you think that this activity was more rewarding to do as a team, or would you have preferred to work alone on it? Why?
6. If you could have used one additional material (tape, glue, wood sticks, foil — as examples) which would you choose and why?

The lesson can be done in as little as 1 class period for older students. However, to help students from feeling rushed and to ensure student success (especially for younger students), split the lesson into two periods giving students more time to brainstorm, test ideas and finalize their design. Conduct the testing and debrief in the next class period.

• Constraints: Limitations with material, time, size of team, etc.
• Criteria: Conditions that the design must satisfy like its overall size, etc.
• Engineers: Inventors and problem-solvers of the world. Twenty-five major specialties are recognized in engineering (see infographic).
• Engineering Design Process: Process engineers use to solve problems. 
• Engineering Habits of Mind (EHM): Six unique ways that engineers think.
• Iteration: Test & redesign is one iteration. Repeat (multiple iterations).
• Patent: A patent for an invention is the grant of a property right to the inventor, issued by a
• country’s Patent and Trademark Office.
• Pendulum: Body suspended from a fixed point so that it can swing back and forth under the influence of gravity. Consists of only a few components: a length of string or wire, a bob or some type of weight, and a fixed point where it is attached to a solid object.
• Prototype: A working model of the solution to be tested.

Internet Connections

• A Walk Through Time

Recommended Reading

• Time’s Pendulum: From Sundials to Atomic Clocks, the Fascinating History of Timekeeping and How Our Discoveries Changed the World (ISBN: 978- 0156006491)
• The Pendulum: A Case Study in Physics (ISBN: 978-0199557684)
• Make Your Own Working Paper Clock (ISBN: 978-0060910662) 

Writing Activity

Write an essay or a paragraph about whether you think a pendulum clock would work on the moon.

Alignment to Curriculum Frameworks

Note: Lesson plans in this series are aligned to one or more of the following sets of standards:  

• U.S. Science Education Standards (http://www.nap.edu/catalog.php?record_id=4962)
• U.S. Next Generation Science Standards (http://www.nextgenscience.org/) 
• International Technology Education Association’s Standards for Technological Literacy (http://www.iteea.org/TAA/PDFs/xstnd.pdf)
• U.S. National Council of Teachers of Mathematics’ Principles and Standards for School Mathematics (http://www.nctm.org/standards/content.aspx?id=16909)
• U.S. Common Core State Standards for Mathematics (http://www.corestandards.org/Math)
• Computer Science Teachers Association K-12 Computer Science Standards (http://csta.acm.org/Curriculum/sub/K12Standards.html)

National Science Education Standards Grades K-4 (ages 4-9)

CONTENT STANDARD A: Science as Inquiry

As a result of activities, all students should develop

• Abilities necessary to do scientific inquiry 
• Understanding about scientific inquiry 

CONTENT STANDARD B: Physical Science

As a result of the activities, all students should develop an understanding of

• Properties of objects and materials 
• Position and motion of objects 

CONTENT STANDARD E: Science and Technology 

As a result of activities, all students should develop

• Abilities of technological design 
• Understanding about science and technology 

CONTENT STANDARD F: Science in Personal and Social Perspectives

As a result of activities, all students should develop understanding of

• Science and technology in local challenges 

CONTENT STANDARD G: History and Nature of Science

As a result of activities, all students should develop understanding of

• Science as a human endeavor 

National Science Education Standards Grades 5-8 (ages 10-14)

CONTENT STANDARD A: Science as Inquiry

As a result of activities, all students should develop

• Abilities necessary to do scientific inquiry 
• Understandings about scientific inquiry 

CONTENT STANDARD B: Physical Science

As a result of their activities, all students should develop an understanding of

• Properties and changes of properties in matter 
• Motions and forces 
• Transfer of energy 

CONTENT STANDARD E: Science and Technology

As a result of activities in grades 5-8, all students should develop

• Abilities of technological design 
• Understandings about science and technology 

National Science Education Standards Grades 5-8 (ages 10-14)

CONTENT STANDARD F: Science in Personal and Social Perspectives

As a result of activities, all students should develop understanding of

• Science and technology in society 

CONTENT STANDARD G: History and Nature of Science

As a result of activities, all students should develop understanding of

• History of science 

National Science Education Standards Grades 9-12 (ages 14-18)

CONTENT STANDARD A: Science as Inquiry

As a result of activities, all students should develop

• Abilities necessary to do scientific inquiry 

CONTENT STANDARD B: Physical Science 

As a result of their activities, all students should develop understanding of

• Motions and forces 
• Conservation of energy and increase in disorder 
• Interactions of energy and matter 

CONTENT STANDARD E: Science and Technology

As a result of activities, all students should develop

• Abilities of technological design 
• Understandings about science and technology 

CONTENT STANDARD F: Science in Personal and Social Perspectives

As a result of activities, all students should develop understanding of

• Personal and community health 
• Science and technology in local, national, and global challenges 

CONTENT STANDARD G: History and Nature of Science

As a result of activities, all students should develop understanding of

• Historical perspectives 

Next Generation Science Standards Grades 2-5 (Ages 7-11)

Matter and its Interactions 

Students who demonstrate understanding can:

• 2-PS1-2.  Analyze data obtained from testing different materials to determine which materials have the properties that are best suited for an intended purpose.

Motion and Stability: Forces and Interactions

Students who demonstrate understanding can:

• 3-PS2-1. Plan and conduct an investigation to provide evidence of the effects of balanced and unbalanced forces on the motion of an object. 

Next Generation Science Standards Grades 2-5 (Ages 7-11)

Engineering Design 

Students who demonstrate understanding can:

• 3-5-ETS1-1.Define a simple design problem reflecting a need or a want that includes specified criteria for success and constraints on materials, time, or cost.
• 3-5-ETS1-2.Generate and compare multiple possible solutions to a problem based on how well each is likely to meet the criteria and constraints of the problem.
• 3-5-ETS1-3.Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved.

Next Generation Science Standards Grades 6-8 (Ages 11-14)

Engineering Design 

Students who demonstrate understanding can:

• MS-ETS1-1 Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution, taking into account relevant scientific principles and potential impacts on people and the natural environment that may limit possible solutions.
• MS-ETS1-2 Evaluate competing design solutions using a systematic process to determine how well they meet the criteria and constraints of the problem.

Standards for Technological Literacy – All Ages

The Nature of Technology

• Standard 1: Students will develop an understanding of the characteristics and scope of technology.
• Standard 3: Students will develop an understanding of the relationships among technologies and the connections between technology and other fields of study.

Technology and Society

• Standard 4: Students will develop an understanding of the cultural, social, economic, and political effects of technology.
• Standard 6: Students will develop an understanding of the role of society in the development and use of technology.
• Standard 7: Students will develop an understanding of the influence of technology on history.

Design

• Standard 8: Students will develop an understanding of the attributes of design.
• Standard 9: Students will develop an understanding of engineering design.
• Standard 10: Students will develop an understanding of the role of troubleshooting, research and development, invention and innovation, and experimentation in problem solving.

Standards for Technological Literacy – All Ages

Abilities for a Technological World

• Standard 11: Students will develop abilities to apply the design process.
• Standard 12: Students will develop abilities to use and maintain technological products and systems.
• Standard 13: Students will develop abilities to assess the impact of products and systems.

Lesson Plan Translation

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