Universal Circular Motion” by Cecilia Liang

Next Generation Science Standards (NGSS)

Materials needed

Universal Circular Motion

HS-PS2-1. Analyze data to support the claim that Newton’s second law of motion describes the mathematical relationship among the net force on a macroscopic object, its mass, and its acceleration.

HS-ESS3-4. Evaluate or refine a technological solution that reduces impacts of human activities on natural systems.

Doc cam Laptop Guided notes Key Points: Uniform Circular Motion (Handout 1) Practice: Uniform Circular Motion (Handout 2) Exit Ticket: Uniform Circular Motion (Handout 3)

Phenomenon

Wind turbines pose a unique and appropriate way to teach circular motion. We will investigate centripetal acceleration and tangential velocity with them. In Germany, wildlife conservation organizations say turbines pose a threat to birds and bats with their rotating blades. This conflict between the development of renewable energy sources and the conservation of endangered species is a “greengreen dilemma” that is much discussed.

Engage

Explore

Explain

Elaborate

Evaluate Students will watch a short introduction video about what wind power is and how it works.

Students will come up with examples of objects which move in circles, then discuss them as a class.

Teacher will review the key points and formulas associated with uniform circular motion, including those for centripetal acceleration and tangential velocity. Students will explain how their examples show the formulas in action, while solving and checking their answers.

Understand: The conflict between the development of renewable energy sources, such as wind turbines, that may pose a threat to birds and bats with their rotating blades and the conservation of endangered species is a “green-green dilemma.”

Assess: Students will research a green-green dilemma in their community/city/state.

Act: Students will create a poster paralleling Germany‘s green-green dilemma they learned about in class, with a dilemma (green-green or not) that they explored within their community. Students will present their poster in class to their classmates, the whole school, and/or community representatives.

Students will assess understanding with an exit ticket.

UNIVERSAL CIRCULAR MOTION

INQUIRY OVERVIEW

The main focus of this lesson will be to introduce students to the concept of centripetal motion by using the example of wind turbines. In addition, students will understand wind energy construction in contemporary Germany and the country’s goal of increasing its usage, whilst further considering the locations of new installations as it relates to wildlife conservation.

At the end of the lesson, students will be able to describe the benefits of sustainable forms of energy, such as wind energy.

TEACHER BACKGROUND

Germany is the third largest producer of wind power in the world by installations, behind China and the USA. Although the wind power industry mostly has popular support, there are groups that oppose the free building of wind farms. Among these groups are wildlife conservation organizations that say turbines pose a threat to birds and bats with their rotating blades. This conflict between the development of renewable energy sources and the conservation of endangered species is a “green-green dilemma” that is much discussed and, at times, tied to political debate. Modern Germany, just like the rest of the world, is continuously finding ways to best innovate sustainably while balancing the opinions of all stakeholders.

Students will need prerequisite knowledge about velocity and acceleration, which will have been covered in the first semester. From there, using the concept of wind turbines is an appropriate introduction to tangential velocity and centripetal acceleration. Common mistakes that might be made on this first day include confusing the directions for tangential velocity (on the edge of the circle), and centripetal acceleration (pointing towards the center of the circle).

SUGGESTED TIME FRAME: 2 Lessons (93 minutes each)

MATERIALS NEEDED

Doc cam Laptop Guided notes

KEY POINTS

Uniform Circular Motion (Handout 1) Practice: Uniform Circular Motion (Handout 2) Exit Ticket: Uniform Circular Motion (Handout 3)

All handouts can be found here

https://tinyurl.com/yyvn7ls9

NEXT GENERATION SCIENCE STANDARDS (NGSS)

HS-PS2-1. Analyze data to support the claim that Newton’s second law of motion describes the mathematical relationship among the net force on a macroscopic object, its mass, and its acceleration. HS-ESS3-4. Evaluate or refine a technological solution that reduces impacts of human activities on natural systems.

KEY LITERACY CONNECTIONS

CCR Speaking & Listening Anchor #1: Prepare for and participate effectively in a range of conversations and collaborations with diverse partners, building on others’ ideas and expressing their own clearly and persuasively. • SL.8.1: “…Pose…specific questions by making comments that contribute to the discussion…” • SL.9-10.1: “... posing and responding to questions that relate the current discussion to broader themes or larger ideas…” • SL.11-12.1: “…posing and responding to questions that probe reasoning and evidence…”

RELEVANT DOMAIN(S) OF DISCIPLINARY CORE IDEAS

Physical Sciences, Technology and Applications of Science

SCIENCE AND ENGINEERING PRACTICES

Students will mainly tackle the idea of different tangential speeds at different points in the blade of a wind turbine. They will discuss how they know why certain places on the blade are more “dangerous” if it hits an animal while rotating.

CROSSCUTTING CONCEPTS

Structure and function Systems and system models

PHENOMENON / MAIN PROBLEM

Wind turbines pose a unique and appropriate way to teach circular motion. We will investigate centripetal acceleration and tangential velocity with them.

In Germany, some wildlife conservation organizations say turbines pose a threat to birds and bats with their rotating blades. This conflict between the development of renewable energy sources and the conservation of endangered species is a “green-green dilemma” that is much discussed. Students will read the article titled “Limits to growth: Resistance against wind power in Germany”:

Wehrmann, B. (2019, March 27). Limits to growth: Resistance against wind power in Germany. Clean Energy Wire. https://www.cleanenergywire.org/factsheets/fighting-windmills-when-growth-hits-resistance

Our physics problems will investigate basic scenarios that could arise from animals/objects being caught in the blades.

ENGAGE - INTRODUCTORY ACTIVITY/HOOK

Students will watch a YouTube video on how wind turbines work:

Energynownews. (2011, December 16). Energy 101: Wind Power [Video]. YouTube. https://www.youtube.com/watch?v=niZ_cvu9Fts.

ANTICIPATED GUIDING QUESTIONS

How does an object “caught” in circular motion move? Will an object move faster or slower depending on where on the circular path it is located?

EXPLORE - GATHERING INFORMATION

Students will take 3 different lengths of string tied to metal washers and attempt to spin them at the same speed. Students will discuss which length of string was “harder” to keep spinning. The idea is that the shorter lengths of string would invariably spin faster because objects with a smaller circular path radius travel with a higher velocity.

EXPLAIN - IDENTIFY POSSIBLE SOLUTIONS

Students will pull prior knowledge about what they know about directly proportional relationships vs inversely proportional relationships. They will be given some time to provide what they think could be possible formulas to calculate centripetal acceleration and tangential velocity.

EXPLAIN

Teacher will write the Key Points (KP) from the “Key Points: Uniform Circular Motion” (Handout 1) on the board.

Students will use the “Practice: Uniform Circular Motion” (Handout 2) to answer questions about the key points presented. #1-2. (4 min) • Students will work with their table on questions #4-10, pushing to use academic vocabulary and talk through problems. (20 min)

Teacher Actions (Handout 1)

Key Point #1: • Teacher will review and explain KP #1. • Teacher will allow students to complete questions #1-2 on with a partner. (4 min)

Key Point #2: • Teacher will review and explain KP #2 with students. • Teacher will model and explain question #3. • Teacher will assign questions #4-10 for group work, circulate, and pull a small group if needed. (20 min)

Key Point #3: • Teacher will review and explain KP #3. • Teacher will model and explain question #11, emphasizing steps needed to calculate the period first, before finding tangential velocity. • Teacher will assign questions #12-13 for students to complete with their table group. Teacher will circulate to look for correct problem set up. (7 min) • Teacher will half-model question #14 to connect to

Newton’s 2nd Law, which indicates that mass times acceleration (in this case, centripetal acceleration), will give centripetal force. Teacher will assign questions

Student Actions (Handout 2)

Key Point #1: (questions #1-2) • Students will copy KP #1 as the teacher is modeling it on the board. • Students will take 4 min to complete questions Key Point #2: (questions #3-10) • Students will copy KP #2 as the teacher is modeling it on the board. • Student will complete question #3 with teacher guidance and ask questions if needed. #14-16 for group work. (15 min)

Key Point #3: (questions #11-16) • Students will copy KP #3 as the teacher is modeling it on the board. • Student will complete question #11 with teacher guidance and ask questions if needed. • Students will work with their table on questions #12-13, pushing to use academic vocabulary and talk through problems. (7 min) • Students will complete questions #14-16, internalizing the connection between Newton’s 2nd Law and circular motion learned today. (15 min)

ELABORATE - TAKING INFORMED ACTION

UNDERSTAND The conflict between the development of renewable energy sources, such as wind turbines, that may pose a threat to birds and bats with their rotating blades and the conservation of endangered species is a “green-green dilemma.”

ASSESS Students will research a green-green dilemma in their community/city/state.

ACT Students will create a poster paralleling Germany‘s green-green dilemma they learned about in class, with a dilemma (green-green or not) they explored that their community faces. Students will present their poster in class to their classmates, whole school, and/or community representatives.

EVALUATE Students will complete “Exit Ticket: Uniform Circular Motion” (Handout 3) to assess understanding. The exit ticket will contain two problems, the completion of which will assess student proficiency in conceptually understanding the formulas for centripetal acceleration and tangential velocity.

VIRTUAL EXCHANGE

A few lesson extensions could investigate the number of actual animal casualties resulting from wind turbines. Students both here and in Germany could gather recent data from their own city on these figures and make an educated proposal about whether or not the issue of environmental conservatism is relevant to a particular area.

CAREER CONNECTION EXPLORATION

Students may have the opportunity to hear from mechanical engineering majors from the local university to hear about what physics classes they have taken and how the topic of circular motion has been touched on. At the end of the potential talk, students will consolidate what they have learned into a KWL chart.

MODIFICATIONS FOR DIFFERENTIATION

Students with IEPs and English language learners will receive accommodated notes with fast-mapped words and bolding and underlining.

*SpEd/ELL students will be provided with student notes that include fast mapping to aid them in experiencing all parts of the lesson smoothly and strengthening their vocabulary. Students will also receive in-class one-on-one support and teacher will have frequent check-ins with students.

Cecilia Liang is an 11th grade STEM teacher at YES Prep Gulfton in Houston, Texas, USA.