Motion in Terms of Position and Time
Lesson 3 of 11
Objective: Through simulations, students will be able to investigate motion in terms of position and time.
The goal of this lesson is to help students use simulations to construct ideas related to the motion of an object. This lesson addresses the HS-PS2-1 and HSN-VM.A.3 standards because it asks students to solve problems related to changes in position in a step-by-step manner. It aligns with the NGSS Practices of Developing and Using models and Using Computational Thinking because students will use a simulation to construct an explanation of the position and velocity of an object. This lesson also is aligned with the NGSS Cross-Cutting Idea of Patterns because students must recognize that the slope of the position vs time graph is the velocity of an object.
Within this lesson, students construct an explanation of the motion of an object beginning with a See-Think-Wonder routine highlighted during the first section of the lesson. Students then use the G.I.R.L.S. protocol to solve a problem that relates to a famous race where a runner slows down and still wins Olympic gold. Finally students, in teams of 2-4, use a simulation to investigate the velocity of an object. During this lesson, I ask students to focus on stretching their prior algebra and physics knowledge to address the factors related to an object's motion. I assess student understanding throughout the lesson using informal check-ins, and assess each student's work at the end of the school day.
See Think Wonder
Many students do not make distinctions between the distance an object has traveled and the displacement of an object from its starting position. I double back to the concept of displacement being the change in an object's position and attempt to remind students of the importance of a starting position for understanding and object's motion in terms of different locations over time. In this lesson, I talk up the idea that the track and field is a model of the importance of a starting position that we can use when trying to understand motion in terms of position and time.
At the beginning of each lesson, I have a quick bell-ringer activity to get students focused on the tasks for today's lesson. There is a slide with the date, the objective and an additional prompt projected on the interactive whiteboard with a red label that says "COPY THIS" in the top left-hand corner. Sometimes the additional prompt is a BIG IDEA for the lesson or the Quote of the Day or a Quick Fact from current events that is related to the lesson. The red label helps my students easily interact with the information as soon as they enter the room and avoids losing transition time as students enter the classroom.
Today's lesson has the big idea about predicting the motion of an objects by studying the pattern of its motion based on time-stamped locations; I want students to consider and make connections to as we move toward interpreting kinematics graphs. I use this big idea because I want students to learn the value testing predictions as a key part of the nature of science.
I have students complete a See-Think-Wonder routine from lesson 3 using an image of Usain Bolt during his Olympic win in Beijing as the visual focus for students during this visible thinking routine. Click here to see an example of student work.
I choose this thinking routine because I want students to look carefully at the runner's motion and to make observations and to interpret motion as the change in position over time.
Once students are done completing the see think wonder activity, I ask students to share out their observations to the whole class by calling on students one at lab station at a time. We watch a video that demonstrates that Usain Bolt slows down to celebrate near the tail end of the race. We also tease out that Usain Bolt's position at the time of the image communicates information about his motion during the race. Then I ask students to give reasons why we should care about the changes of Usain's position over time. I ask this series of questions because I want students to start the sample problem with position and time in mind.
Students are tasked with using the G.I.R.L.S. protocol to answer a Sample Problem for Motion in Terms of Position and Time. I create this problem without using the terms speed or velocity because I want students to know how to determine the physical quantities and then assign common variable names afterward. This way students are building academic definitions for physical quantities based on observations and logic not by rote memorization.
Once students are done with the Sample Problem, I ask students to create either a user guide, an infographic or information cube about their predictions of how fast Usain Bolt could have run if he had not slowed down during the last 20 m of the 100 m dash. This user guide activity relates to section c of the sample problem. Click here to see an example of student work.
Once students have completed their visuals, I ask them to share them with their table mates and to spend 5 minutes critiquing each others' work and making adjustments accordingly before submitting them for assessment by me. This sample problem is useful because I wanted students to make connections between motion and unit conversions. I also wanted students to see that physics skills can help them answer real questions that may arise when events like world records in sprinting are shattered.
I use simulations throughout this course because I want students to learn to leverage technology as an entry point to becoming scientifically literate in the 21st century. Explore learning has an extensive set of science simulations called Gizmos that allow students to make and test predictions related to physical phenomena. This simulation is beneficial because I am introducing kinematics graphs. Students come to understand how the shapes and characteristics of the graphs allow them to make assertions about the motion of an object.
Students work in teams of 3-4 during this part of the lesson. During the first five minutes of this section, students answer prior knowledge questions where they compare the motion of two runners given each runner's change in position in a particular time period. Students spend the next twenty minutes manipulating the runners in the simulation and recording what happens during the race in terms of the graphical output that the simulation produces.
Use the student exploration sheet found here for the activities that correspond to the simulation. The first asks questions about a single runner's position. For example: What does the y-intercept tell us about the runner? The second activity asks students to generate graphs that correspond to runner's speed and direction. For example, during the second activity students create graphs that correspond to a runner moving from left to right and then rests. The third activity asks students to use the simulation to model a race between two runners for several outcomes. For example, students change simulation inputs to create an outcome where the first runner wins against a second runner who has a head start. After 45 minutes elapse, I collect the activity sheets to grade and return to students by the end of the week.
I provide students with an Exit Slip with a set of writing prompts for a routine called compass points, where students are tasked with both identifying their personal level of understanding of the pertinent and puzzling portions of the lesson as well as a point of transformation in their personal understanding of a topic. I implement this type of closure activity because it encourages students to focus on how access to new information affects their viewpoints on a scientific topic. To wrap up the lesson, I remind students that we will go over the feedback from their exit slips at the end of the week.