BOBO EXPLORES LIGHT overview
Lesson plan Overview
We found great value in using the reflection chapter of Bobo Explores Light to give students the opportunity to explore how light reflects, learn about angles of incidence, hypothesize and make inferences on the laws of reflection, and write in their own words about these topics after thorough research. Students manipulate the positioning of four mirrors and a laser on screen and turn the laser to observe the angles of reflection that form when the light reflects off the mirrors. They turn on Bobo’s 3D projector to compare the incoming and outgoing angles and the angles of incidence and reflection. Small-group and full-group discussions are facilitated as these activities progress.
Describe the behavior of photons when they hit reflective surfaces.
Explain the relationship between the angle of incidence and angle of reflection.
Formulate a definition of the laws of reflection.
STEP 1. Ask students, "On what surfaces can you see your reflection?" and write down brainstormed suggestions of different items and materials.
STEP 2. If time and materials allow, have students demonstrate and test against various surfaces (mirror, water, glass, metal, computer screen, etc).
STEP 3. Ask students, "On which of these surfaces can you see yourself most clearly?"
STEP 4. Open Bobo Explores Light to the section on reflection. Ask students to arrange the mirrors on the iPad screen, then turn on the laser. Explain the angle of incidence (where the light strikes the surface) and the angle of reflection.
STEP 5. Ask students, "What patterns do you see with the angles?" Ask students to rearrange the mirrors and observe the angles again.
STEP 6. Ask students, "Has anything about the angles changed?" Ask students to hypothesize the relationship between the incoming and outgoing angles.
STEP 7. Turn on the 3D presentation tool. Ask students, "Does the information on the angles confirm the class hypothesis?"
STEP 8. Ask students, "What can we infer about the Laws of Reflection?" Ask students to research and write the Laws of Reflection in their own words.
STEP 9. Have students read through the text for additional information and fun facts about mirrors and reflection.
Lesson Steps Version 2
STEP 1. Guide students to "Reflection" section of Bobo Explores Light menu.
STEP 2. Allow student groups to move the mirrors and observe what happens to the laser. One student controls the iPad while the group members watch.
STEP 3. Ask them to do a series of challenges. In these challenges, the location of the laser's source is stationary.
Challenge 1: Use one mirror placed in three different locations to hit Bobo.
STEP 4. Then have them tap on Bobo's antenna to see the normal with the incoming and outgoing angles. Have students make further observations to develop postulates regarding the incoming and outgoing angles.
STEP 5. Now have students experiment with both string and a real mirror (note: provide PDF of person reflecting in a mirror). Ask them to develop three questions and use the mirror to provide answers. For example, "What's necessary to see my friend in the mirror?" and "Does the distance from the mirror change my postulate about incoming and outgoing angles?"
*Pay close attention to questions the students ask because they often reveal their misconceptions.
STEP 6. Student groups return to Bobo Explores Light and use all four mirrors to direct the light to hit Bobo's eye. Then have them take snapshots of their solutions.
STEP 7. Use that snapshot to measure with a protractor the incoming and outgoing angle of each light reflecting off the mirror. Students record the angles of each mirror onto paper or a digital device.
STEP 8. String activity: make predictions using Laws of Reflection. One student stands a short distance from the wall with one end of a piece of string. The team picks a point on the wall and places the midpoint of the string at that point. Using a protractor, the team determines the "incoming" angle. A second student takes the other end of the string and stands at a distance from the wall. The team measures an equal angle for the "outgoing" angle and places the second student at the end of the string along that angle. Now place a mirror at the location where the string meets the wall. You will see the person in the mirror.
STEP 9. Using the mirrors provided, students duplicate that solution in the physical realm with one student (per group) as the source of light in place of the laser. Student groups then snap a picture of their solution.
STEP 10. Upload the two pictures to the Learning Tool (LT) and complete the Learning Opportunity.
Students can articulate the concept of reflection and the incoming angle the normal line.
Students demonstrate the ability to predict that angle of reflection increases based on the increased angle of rotation of the mirror.
Students understand that there are many truths in science that can be observed but few that can be used as tools for prediction.
Students identify and understand the use of the normal line.
Students identify the normal line and create a rule of reflection that allows us to predict.
Students capture photos of each solution on the iPad. They also give answers to the following questions, either in writing or orally:
- What can you observe about distance of the mirror?
- How does the angle change based on the distance you place the mirror from the laser?
- How does the angle between the two beams change based on how much you rotate the mirror to make the beam move towards Bobo?
- Do they get larger or smaller when you rotate the mirror away from the laser and towards Bobo?
Example “talk through” for understanding Normal line and incoming and outgoing angles.
Teacher: What do you notice when you click on Bobo’s antenna?
Student: I notice red and blue numbers called the incoming angle and outgoing angle.
Teacher: What else?
Student: The numbers are red and blue and the curved dotted line is also red and blue.
Teacher: What else?
Student: The red and blue curve has a line going through the center.
Teacher: Ok, great. Now rotate the mirror away from the laser. What do you notice about the white line when you rotate it?
Student: The line stays pointing straight from the mirror.
Teacher: Ok, lets call that 90 degrees. What do you notice about the red and blue numbers when you rotate the mirror away from the laser and then back towards it?
Student: The numbers get larger then they get smaller.
Teacher: Great, let’s do it again! What else about the two numbers do you notice?
Student: They are the same!
Teacher: What rule can we create from this?
Student: For reflection, the incoming angle is always equal to the outgoing angle.
Common Core - English Language Arts
Science and Technical Subjects
CCSS.ELA-Literacy.RST.9-10.7 Translate quantitative or technical information expressed in words in a text into visual form (e.g., a table or chart) and translate information expressed visually or mathematically (e.g., in an equation) into words.
CCSS.ELA-Literacy.RST.11-12.9 Synthesize information from a range of sources (e.g., texts, experiments, simulations) into a coherent understanding of a process, phenomenon, or concept, resolving conflicting information when possible.
CCSS.ELA-Literacy.WHST.9-10.2 Write informative/explanatory texts, including the narration of historical events, scientific procedures/ experiments, or technical processes.
1. Creativity and Innovation
Use models and simulations to explore complex systems and issuesIdentify trends and forecast possibilities
2. Communication and Collaboration
Interact, collaborate, and publish with peers, experts, or others employing a variety of digital environments and mediaCommunicate information and ideas effectively to multiple audiences using a variety of media and formatsContribute to project teams to produce original works or solve problems
3. Research and Information Fluency
Plan strategies to guide inquiryLocate, organize, analyze, evaluate, synthesize, and ethically use information from a variety of sources and mediaEvaluate and select information sources and digital tools based on the appropriateness to specific tasksProcess data and report results
4. Critical Thinking, Problem Solving, and Decision Making
Identify and define authentic problems and significant questions for investigationCollect and analyze data to identify solutions and/or make informed decisionsUse multiple processes and diverse perspectives to explore alternative solutions
5. Digital Citizenship
Advocate and practice safe, legal, and responsible use of information and technologyExhibit a positive attitude toward using technology that supports collaboration, learning, and productivity6. Technology Operations and Concepts
Understand and use technology systemsSelect and use applications effectively and productivelyTransfer current knowledge to learning of new technologies