The goal of this class is for students to learn about the different wave phenomena and characteristics and then be able to apply them to different problems. In this lesson students use notetaking strategies to help them to take in information from other groups presentations. The presentations were prepared in the previous lesson with their table groups. The presentations help to work on Science and Engineering Practice 8 concerning evaluating and communicating information. One of the presentations discusses the evidence supporting wave-particle duality which coincides with HS-PS4-3. After the presentations, students use what they learned and apply it to different problems about various phenomena.
To start out class, I have students do a warm-up question that deals with the wave equation. They write this problem on the back of their wave unit packet. I do this because there seemed to be a little difficulty with a few problems that they completed on the wave equation worksheet in previous lessons and I want them to continue to practice these types of problems. I have the question on the board (as shown below) when they come into class and I give them about 5 minutes to work on it individually.
After about 5 minutes, I ask volunteers to help me to work through the problem explaining their work for each step. I do this so other students can see how students thought to do this problem. I focus especially on finding speed because there are multiple ways to figure this out. They can find speed by using the frequency times the wavelength or the wavelength divided by the period.If the class only used one way, I ask them what would be another way to find this so students can be encouraged that there are multiple ways to solve some types of problems. The answers to this question are as follows: amplitude=16 cm, wavelength=96 cm, period=0.42 s, and speed=230 cm/s.
After the warm-up question, I ask students to open to their presentations; I give them a few minutes to look over them with their group before we start. About 5 minutes later, I ask students to turn to the Sound and Light Properties Table in their packets because this is where they take notes. Before we begin the presentations, I tell students that I want them to make some predictions about whether the characteristics are seen only in sound, only in light or in both by making a check mark in the left column of their paper, as shown in the student work below. This gets them thinking about the characteristics and will be helpful for them as we actually identify which characteristics are exhibited in sound and/or light after the presentations.
After their predictions, I have each group come to the front to present their information to the class. I ask them to present in the order of definition, facts/characteristics, examples and non-examples so as to remain consistent for audience members. While each group is presenting, I expect that each group member presents one of the boxes (since there are about 4 members in every group) so that each person participates. As audience members, I expect students to be taking notes in their Sound and Light Properties Table and asking questions at the end of the presentation if they do not understand. Examples of groups' presentations are shown in the Be the Expert Presentations.
After each presentation, I ask the group if they found that phenomena or characteristic was found in sound, light as a wave or light as a particle. After the group has answered, I tell the students if they are correct or not so they can mark it on their sheets. If the group was incorrect, I explain why so they know the reasoning behind that categorization. A student's work is shown below for the "After Presentation" categorization.
After the presentations, I have students look at the wave characteristics. This is a worksheet that I create that gives them a little more practice with some of the wave phenomena from the presentations. All of the questions on this worksheet come from the Conceptual Physics textbook. Before they start working on the worksheet, I model for them how they should answer the questions. I tell them that the first column has the question or problem they have to solve; the second column is where to write their answer with an explanation; and the third column they must identify which wave characteristic/phenomena it is about.
To show students an example, I read the first problem and then I ask them what wave characteristic they think it is talking about. They respond with interference which is correct. The wave characteristics are pretty obvious to the students as they work through this worksheet. After we identify the characteristic, I tell them we need to breakdown the problem. We look at each wave and identify if it is constructive or destructive interference, remembering that constructive means adding the amplitudes and destructive means subtracting the amplitudes. When we have identified all four, I tell the students that I want them to rank them on their own, based on what we have discussed. I allow them to have about 10 minutes to work on the worksheet. Whatever they do not finish in class, they complete for homework.
To end class, I give each student a green and a red post-it to complete an exit slip. I ask students to write something they learned in this lesson on the green post-it and a question they have on the red post-it.
I do this because students heard a lot of information from the presentations; I want to give them an opportunity to reflect on what they actually learned from the presentations. The questions help me to see where there is confusion so I can focus more on these concepts in the next lesson through the wave characteristic worksheet and the wave stations lab.