Motion of the Ocean (Part 1/2)
Lesson 6 of 18
Objective: SWBAT describe the motion of objects in different ways.
Middle school students are always moving, so the study of motion should feel right at home. I use the Motion of the Ocean lesson as an introduction to basic kinematic concepts, such as motion, scalar and vector quantities, and distance and displacement, so that students have a basic understanding as they move forward in the design of speed, acceleration and Newton's Laws of Motion investigations (MS-PS2-2). This lesson can be used as is, split into individual learning segments or jazzed up with additional demonstrations, visuals and demonstrations.
As students work through this lesson, they use science practices such as analyzing and interpreting data (SP4) and using mathematics and computational thinking (SP5) to construct a conceptual understanding of motion. Students also access Common Core Mathematical Standards in Expressions and Equations when they practice calculating speed and acceleration.
The Motion of the Ocean is a guided concept-building exercise including lessons taught over the span of two or more days. The activity relies heavily on rigorous student thinking, so spacing it out over several days can help minimize student burn-out. To help manage the magnitude of this activity, you will find the project split into two parts.
In order to ENGAGE students in this lesson, they analyze the following photo. To excite students about the photo, I use a story-telling strategy by explaining how "in the olden days", there was an argument about whether or not horses could have all four hooves off the ground at the same time. I explain that this photo represents a series of photos taken in sequence. They analyze the photo individually in a one-minute silent thinking session using the following prompt:
Using the photo, what evidence can you observe that shows that the horse was moving at the time the photos were taken.
Students share their evidence about how they know the horse was moving. A strategy to use during this discussion is the "link back to the objective" or "Socratic questioning" strategy. This strategy is a discussion technique where the teacher directs student responses back to the learning objective to move the discussion toward that objective. As students share in this instance, my objective is to develop a definition of motion. While students may or may not be able to generate a scientific definition of motion when asked at the onset of the lesson, they certainly have enough background knowledge and evidence generated from the photo to construct a definition collaboratively through discussion. By asking the right questions to drive the discussion toward the end objective, students discover the definition through critical thinking without simply being told the definition. Some common "Listen Fors" that move the discussion toward the objective are:
1) The horse's body changes position with respect to the line on the wall.
2) The horses tail and legs are in different positions compared to the other photos.
3) The jockey's coat is in different positions compared to the other photos.
All of these pieces of evidence lead to the idea that motion is a change in position between objects or between an object and a reference point. Teacher questions like:
1) How do you know the horse is moving and it isn't just that the line in the wall is moving? or
2) What two things are you comparing to prove the horse is moving?
...help link the discussion back to the learning objective of defining motion.When the discussion arrives at (or near) the definition, have students write it down in on the Motion Student Handout.
Explore and Explain
The EXPLORE stage of the lesson is to get students involved in the topic so that they start to build their own understanding and the EXPLAIN stage provides students with an opportunity to communicate what they have learned so far and figure out what it means. This stage of the lesson presents many great opportunities for quick formative assessment.
To help students explore and explain what they are learning, follow an "I - We - You" progression to make mental models of the different concepts. First, model for students how to complete the concept boxes by explaining how to:
1) Think about the word and activate prior knowledge to develop an initial definition or image. This step mimics the idea of creating a scientific hypothesis, but in this case, I call it a an "idea hypothesis.
2) Find evidence (using a textbook or previewed Web-sites) to test their idea hypothesis about the concept;
3) Paraphrase a scientific definition and draw scientific diagrams with labels that show understanding rather than simply copying the information.
Thinking out loud during this portion of the progression models the cognitive process of making meaning. Secondly, complete the process together with students providing the out loud thinking. Gradually release control to students to working individually (or in small groups) to complete the process independently.
Since the concepts are very dense, give students enough time to complete one part of the Motion Student Handout at a time. Walk the room to gauge progress and pull the class back together to review that one part of the activity. I again model for students how to neatly complete the activity and we briefly discuss each topic as we review using the Motion Student Handout Answer Key. During the review, student answers and explanations can offer quick formative assessment. Students can also ask questions about parts of the activity they don't yet understand.
Following this pattern of work and review, students complete the activity. When we finish reviewing, I offer students a clean, simplified copy of the notes: Simple Motion Notes.
Teacher Note: Providing students with a curated set of resources to use helps facilitate the process of making meaning. Since this is an introductory activity meant to draw on students' prior knowledge, it is important to have developmentally appropriate resources at the ready. Many online resources are too difficult, but I've had luck using our textbook and the Physics Classroom web-site.
Continue on to Motion of the Ocean Part 2.